231 



uun 






m 



m 



mmm 

'1? 



^M! 








1 
■ 



li ! 



~'-cv A' 



■^% 



^V ■'■t: 







A-^ .^ >i:L ..^ 



^.<^ : 



0' ."^ ' *, ^ 



.0 0^ 



: \^^ \ 



:v-\^^ 



o 0' 






•^,^^ 

.s^-^^. 



>A^^ ^-^^ 






.0 o 







\-^' 



^>^ ^ \^ViS^^ S- v^X 







THE SCHOLASTIC THEORY 

OF THE 

SPECIES SENSIBILIS 



DISSERTATION 

Submitted to the Faculty of Philosophy of the 
Catholic University of America 



In Partial Fulfillment of the Requirements for the 
DOCTOR OF PHILOSOPHY 



BY 

OTHMAR F. KNAPKE, C.PP.S. 

Catholic University of America 

1915 






Copyright, 101 S 

BY 

Othmar F. Knapke. 



m S5ISI5 

©CI,A40fi321 



National Capital Press, Inc. 

Book Manufacturers 

Washington, D. C. 



'-< f / 



DEDICATION. 

To my esteemed teachers 

Dr. Turner, Dr. Pace, and Dr. Fox. 



CONTENTS. 

Page 
Introduction 5 

Chapter I. 
The Psychical Aspect of the Species Sensibilis 14 

Chapter II. 
The Materialistic Aspect of the Species Sensibilis 38 

Chapter III. 

The Psycho-physical Aspect of the Species Sensibilis 60 

Conclusion 99 

Bibliography 103 



THE SCHOLASTIC THEORY 

OF THE 

SPECIES SENSIBILIS. 

Introduction. 

Contemporary philosophy is interested in the theory 
of knowledge more than in any other branch of specula- 
tive thought. Before we philosophize we are asked to 
demonstrate the possibility of knowledge, and in order to 
do this, we must determine the nature of knowledge. But 
' ' to define knowledge apart from the process by which it 
is acquired, is impossible. ' '^ Hence we must go back one 
more step and investigate the origin of knowledge. 

This critical attitude towards philosophy was inaugu- 
rated by Kant, who attempted to reconstruct the condi- 
tions of knowledge. From his day to our own the bulk of 
speculative thought has centered around epistemology, 
so much so that some philosophers would even discredit 
all other metaphysical speculation. 

The philosophers of old were not so intensely critical. 
For them the possibility of knowledge was an hypothesis, 
not a thesis ; the objective truthfulness of our knowledge 
was taken for granted, not proved. There was, however, 
one problem of epistemology which troubled philosophers 
even before the time of Aristotle, namely, the problem of 
sensation. All knowledge, argued these thinkers of old, 
implies a union of some kind between the knower and the 
thing known. But in sight, for instance, the object is not 
in immediate contact with the eye ; in fact, we can see only 
those objects which are a distance from us. What is 
more, we see these objects as existing, not within the eye, 
but outside of ourselves. How, then, is the necessary 
union between subject and object established? Does the 
eye go out to the object? — this was probably the most 



Walker, Theories of Knowledge, p. 375. 



6 THE SCHOLASTIC THEORY OF 

primitive solution — or, does the object enter the eye! 
This second alternative was the basis of the earliest sys- 
tematic theory of sensation, formulated by Democritus. 

As an atomist, Democritus maintains that the whole 
universe is material, that all matter is composed of atoms, 
and that all movement is the result of material contact. 
Sensation, then, as well as thought, must be a corpo- 
real phenomenon, must be the action of body upon body. 

Tds aia^rjaeLS Kal rds vorjcreLS erepwaeis tlvai rod acofxaros.^ 

Hence he maintains that sensation is effected by the 
emanation of atoms from the object which form an 
d8ui\ov or image of the object in the contiguous air.^ 
This eWcoXov is a material shell, film, or cast given off 
from the surface of the object.* The air, being made 
dense by the sun, is stamped with this eidui\ov and con- 
veys it to the eye.^ But the air, as well as the eye, modifies 
the image. "^ Thus modified, it passes to the soul through 
the body, and produces in the soul (which is but a finer 
matter similar to fire) a qualitative change." The same is 
true for all the senses ; they are struck by etSuXa or ema- 
nations of atoms which, by passing through the organ, 
come in contact with the soul.^ Although the ddwXa strike 
our whole body, we see with our eyes and hear with our 
ears because the organs of sense are freer passageways 
to the soul.'* 

As long as men accepted materialistic monism, this 
solution of Democritus might satisfy them ; but with the 
advent of dualism, new difficulties arose concerning sen- 
sation. If the mind or spirit is a substance wholly differ- 
ent from, if not indeed directly opposed to matter, how 
can a material object become united to a spiritual subject? 



2 Diels, Vorsokr., I, p. 34.8. 

3 Ibid. 
' II)id. 

6 Op. cit., p. 374. 
« Op. cit., 373. 
^ Op. cit., p. 370. 
« Op. cit., p. 374. 
» Op. cit., p. .375. 



THE SPECIES SENSIBILIS 7 

Again there could be but two solutions: either the sub- 
ject goes out to the object, as Plato holds ; or the object 
comes to the subject, as Aristotle maintains. 

Plato developes a system of idealism. Mind is all-im- 
portant; matter is "nearly nothing." Space and move- 
ment are real, but the objects moving in space are only 
phenomena,^*^ that is, they belong to ' ' the region of change 
and multiplicity and imperfection and, therefore, of par- 
tial not-Being."" But the object of true knowledge is 
the universal, the idea. "The Idea is the element of 
reality in things — the one uniform immutable element, 
unaffected by multiplicity , change, and partial not- 
Being.'"^ Ideas, moreover, are innate. These metaphys- 
ical principles lead Plato to underestimate sensation 
which deals merely with what is phenomenal. What is 
more, sensation positively disturbs the ceaseless activity 
of the soul." 

But the fact remains ; we know objects of sense. How, 
then, can we account for this phenomenon? Plato says, 
since the body is material and, therefore, phenomenal, it 
can be influenced by external objects. This influence 
from without is conveyed to the soul through the body, 
i.e., we have sensation.^* Impressions on the body arise 
from movement." Various movements affect the body 
differently, hence the different qualities of sensation." 
The quantity of sensation is determined by the strength 
of the impression and by the fineness of the sense-organ." 

How this movement comes in contact with the organ 
of sense, Plato explains only in the case of sight, which 
he describes as the result of a ray of light going out from 
the eye, meeting the light without, and thus forming a 

10 Timaeus, 53. 

" Turner, Hist, of Philos., p. 106. 

^ Turner, op. cit., p. 100. 

" Tim., 43. 

" Tim., 43. 

•5 Tim.. 66. 

le Phileb., 33. 

"Tim.. 75. 



8 THE SCHOLASTIC THEORY OF 

stream of light. When an object comes in contact with 
this stream, it gives to the latter a specific motion which 
then is carried to the sense-organ. From the organ it is 
conveyed to the soul by the movement of contignious 
particles." 

The soul is not affected or changed by these impres- 
sions from without ; but in the affection of the body, the 
soul perceives the object of sensation." Neither does the 
influence of the object determine the soul, as the soul is 
ceaseless activity and, hence, determines itself.-" 

Aristotle was not satisfied with either of the above 
theories of sensation. Democritus' theory he rejected, 
because ''it is absurd to say with the ancients that colors 
are effluxes and for this reason are visible. For, in their 
opinion it is absolutely necessary that sensation be ef- 
fected through contact ; it is consequently better to say at 
once that the medium of sensation is set in motion by the 
sensible object, and that in this way sensation is produced 
by contact and not by effluxes. ' '-^ 

The Platonic theory of sensation was equally unsatis- 
factory to Aristotle, according to whom ideas are not in- 
nate, but have an existence in the objective world. Our 
knowledge of them must consequently be based on sensa- 
tion, i.e., sensation furnishes the material out of which 
the intellect forms its ideas. "Thought is impossible 
without an image ... an image is the product of sensa- 
tion."^^ Led by these convictions, Aristotle treats of sen- 
sation with surprising completeness. Siebeck thinks that 
the theory of sensation is not only the most thorough trea- 
tise of Aristotle's psychology, but that it likewise shows 
the greatest advance over earlier philosophy.- 

Three metaphysical concepts are fundamental in the 



'8 Tim., 45. 

19 Tim., 45. 

20 Tim., 43. 

21 De Sens., Ill, 15. 

22 De Mem., I. 

23 Gesch. d. Psychol.. F, p. 21. 



THE SPECIES SENSIBILIS 9 

theory of sensation as presented by the Stagirite ; namely, 
the substantial unity of body and soul, matter and form, 
and actuality and potentiality. If any one of these be 
rejected, his theory of sensation will fall; but if all three 
are accepted and understood, his theory of sensation will 
be both intelligible and satisfactory. 

Sensation, Aristotle goes on to explain, arises from 
the action of the object on the subject.^* The object of 
sensation is the material universe ;^^ the subject is neither 
the body nor the soul separately, but the two united as 
one substance. ' ' Sensation in its actual sense is a psychi- 
cal process mediated by the body."^" The influence of 
the object Aristotle explains thus: the sense qualities, 
e.g., color, sound, and odor, are kinds of motion 
{m>r}a-€Ls) .^"^ The objects in which these qualities inhere, 
communicate them 'Ho a certain part of the atmosphere, 
and this in turn sets another part in motion. "^^ Thus 
''the sense-organ is stimulated by the contiguous me- 
dium."-^ Simultaneously with this stimulation the dor- 
mant, potential faculty of sense becomes actual and per- 
ceives the object. "The actualization of the object of 
sense and of the sense itself is one and the same process ; 
they are not however identical with each other in their 
essential nature."^" It follows, then, that the sense is 
representative what the object of sense is entitative. 

However, "the mode of expression of the perceptive 
faculty and of sensation is not magnitude, but only a 
certain relation and potentiality of magnitude. ' '^^ How, 
then, can sensation be caused by material things which 
are magnitude! "A sense is capable of receiving into 
itself sensible forms without their matter, just as wax 



2* De An., II, 5. 
^ De An., I, 4. 
26 De Som., I, 5. 
2' De An., II, 2. 
28 De Insomn., II. 
23 De An., II, 7. 

30 De An., Ill, 2. 

31 De An.. II, 12. 



10 THE SCHOLASTIC THEORY OF 

receives into itself the mark of a ring without its iron or 
gold; ... it receives into itself a gold or bronze 
impression, but not as gold or bronze. In like manner 
also sense is impressed by every object that possesses 
color or flavor or sound, not in so far as each of these 
objects bears a given name, but in so far as it has such 
and such a quality and expresses an idea. The organ of 
sense is fundamentally that in which this power of being 
impressed exists. It has, therefore, an identity with the 
object that makes the impression, but in its mode of ex- 
pression it is different. ' '^^ The subject becomes identical, 
not with the thing perceived, but with its form. "It is 
not the stone which is in the soul, but the form of the 
stone. "^^ 

Here we have the most characteristic feature of Aris- 
totle's theory of sensation: material objects act upon the 
sense in virtue of their form {tvtos, el8os). Thus the 
chasm between mind and matter is bridged over more 
satisfactorily than by any previous theory. Idealism is 
avoided — the objects really cause sensation; materialism 
is avoided — sense is informed by the form, not by the 
matter, of the object. 

Siebeck says of this theory: "In der Geschichte der 
Wissenschaften gehort die Sinnesphysiologie des Aris- 
toteles zu den bedeutendsten Erscheinungen und ist wie 
weniges epochemachend. Was an ihr im Vergleich mit 
der heutigen unzulanglich ist, beruht fast ausschliesslich 
auf der Unbekanntschaft der Nerven-und Gehirnfunc- 
tionen. Das erkenntnisstheoretische Problem aber ist 
in derselben tiefer ergriffen, als es in der Kegel heute 
auf diesem Gebiete geschieht."^* 

Aristotle was followed by a period of intellectual de- 
cadence when problems of philosophy were solved, not by 
thought and research, but upon the authority of earlier 
philosophers. Hence we need not record tlie theories of 



32 De An., II, 12, 

33 De An., Ill, 8 
" Op. cit., p. 39. 



THE SPECIES SENSIBILIS 11 

sensation wliicli prevailed during that time. Lacking in- 
dividuality and depth, they are so many copies or modifi- 
cations of one or the other theory outlined above. 

The Scholastic philosophers of the Middle Ages form- 
ulated the theory of the species sensibilis as an explana- 
tion of the problem of sensation. They claimed to have 
borrowed this from Aristotle. But in modern times it 
has been said over and again that they misinterpreted 
Aristotle and approached rather the theory of Democri- 
tus. For this reason, the theory of the species sensibilis 
is rejected en masse without investigation. Now it 
is quite possible, even likely, that some contemporary 
philosophers reject this doctrine of the Scholastics, as 
they do many others, not because it is known to be false, 
but because it is falsely known or not known at all. Ex- 
cept in rare cases, it is known only from secondary, 
if not from biased sources. But as Roger Bacon advises 
us: "Nonpossumus (eorum) philosophorum sententiam 
deprehendere, nisi ex libris eorum testimonia propria 
eruamus, ut sic vel errantes damnemus ex propriis verbis, 
vel excusatos a dentibus vulgi imperiti liberos extra- 
hamus.'"^ Hence a presentation of the historical devel- 
opment of the species-theory from the beginning of Scho- 
lasticism to St. Thomas, based on original sources, will 
not be out of place. Such is the purpose of this treatise. 

The theory of the species sensibilis is not a physical 
or a physiological theory. As the opponents of medieval 
philosophy will readily concede, the Scholastics were 
inclined to speculation rather than to observation, to de- 
duction rather than to induction. Starting, then, from the 
principle that in all knowledge the thing known is some- 
how in the knower, they were absorbed in the problem of 
sense-knowledge. How can a material object be in the 
sense which is a psychical faculty? How can a psychical 
faculty be excited to action by a material impression? It 
was not a question of what does take place and how, but 



^ Op. maj., (Bridges), p. 112. 



12 THE SCHOLASTIC THEORY OF 

what must take place and how can it. And the outcome of 
these inquiries was the theory of the species sensibilis. It 
is, then, truly a metaphysical theory, something over and 
above the physical — not the result of observation, but a 
postulate of reason. The naive physical and physiologi- 
cal views with which some of the Scholastics surrounded 
the species-theory, are not a necessary part of it. They 
may be rejected — in fact, many of them have been re- 
jected — without affecting the theory itself. Hence the 
present treatise will present the development of the meta- 
physics of the species-theory with only cursory refer- 
ences to the accompanying physical and physiological 
views. 

Scholasticism is sometimes pictured as a closed, static 
system of thought, based in a large measure on authority, 
human and divine, with no development or evolution. 
There may be some ground for this accusation in the de- 
cadent Scholasticism of the fourteenth and fifteenth cen- 
turies. But herein Scholasticism is no exception. His- 
tory attests the sad fact that all great intellectual gen- 
iuses have been unfortunate in so far that their ideas 
were not developed, sometimes not even fully understood, 
by their immediate successors ; the pupil contented him- 
self with restating the words of the master instead of 
extending their application. 

Scholasticism in the period of its development before 
St. Thomas, presents another picture. The theory of the 
species sensibilis, for instance, in the eleventh century 
is so different from this same theory in the thirteenth 
century, that we should hesitate to apply to the former 
the name of species-theory, were it not suggested by the 
natural historical development. In fact, as we find three 
general views regarding sensation itself, the psychical, 
the materialistic, and the psycho-physical view; so, too, 
we find in the history of Scholasticism three aspects of the 
species sensibilis, the psychical, the materialistic, and the 
psycho-physical. 



THE SPECIES SENSIBILIS 13 

The psychical aspect of the species sensibilis, which 
is chronologically the first, is particularly noticeable in 
St. Augustine, Scotus Eriugena, and St. Anselm. These 
emphasize, more than do other Scholastics, the activity 
of the soul in the formation of the species, to the neglect 
of the influence from the external object. 

Opposed to this view of the species is the materialistic 
aspect, according to which the species proceeds solely 
from the object, is material, indeed, is little more than the 
physical or chemical qualities that affect the organ of 
sense. The Arabians introduced the materialistic aspect 
of the species sensibilis, which is so evident in the School 
of Chartres, the School of St. Victor, Alfred of Sareshel, 
and others of the twelfth century. 

Finally we see the psycho-physical aspect of the 
species sensibilis. This is a return to the original elSos- 
theory of Aristotle, modified to some extent both by the 
psychical and by the materialistic views which preceded 
it. The great Scholastics of the thirteenth century are ex- 
ponents of this view. 

From this historical presentation it will become clear 
that many objections, which have some weight if urged 
against the first or second aspect of the species sensibilis, 
lose all foundation if directed against the theory as de- 
fended by the great Scholastics of the thirteenth century. 

It would, however, be both tedious and useless to pre- 
sent the application of the theory of the species sensibilis 
to each of the five senses. The problem of sensation is the 
same in one as in the others. Hence we shall be guided 
by the words of St. Augustine : ' ' Sed et multum est, et 
non necessarium, ut omnes hos quinque sensus id quod 
quaerimus, interrogemus. Quod enim nobis unus eorum 
renunciat, etiam in ceteris valet. Itaque potissimum 
testimonio utamur oculorum. Is enim sensus corporis 
maxime excellit. ' '^^ 



3» De Trinit., XI, c. 



CHAPTER I. 
THE PSYCHICAL ASPECT 

OF THE 

SPECIES SENSIBILIS. 

ST. AUGUSTINE.— 8t Augustine is usually classed 
with the patristic philosophers. But the early Scholastics 
are so generally dependent upon him as their guide and 
their authority, that, in order to understand any Scho- 
lastic doctrine in its earliest phase, it is helpful, if not 
indeed necessary, to examine first St. Augustine's view of 
this doctrine. 

In psychology as well as in epistemology, St. Augus- 
tine is a Platonist. Recently some writers have brought 
out the Aristotelian elements in his psychology.^' He 
does say that soul and body form one substance, that the 
soul gives being and species to the body.^^ But these are 
barren principles that do not in any way influence the 
general tone of his psychology. When he speaks without 
restraint he is thoroughly Platonic ; the soul is ' ' substan- 
tia quaedam rationis particeps, regendo corpori accom- 
modata" ;^^ man is a rational soul making use of a mortal 
terrestrial body ;*° as every spirit is by its nature superior 
to the most perfect body, as God is superior to all crea- 
tures, even so the soul is superior to all matter.*^ 

His epistemology, too, is Platonic. ''Scientia insita 
est nobis ";*^ learning is a process of remembering and 
recalling ;^^^ though hidden and obscure, ideas are in the 
mind before they are learnt.^* As Martin says of him: 



3^ Cf. Rev. Neo-scolast., May, '0-1. 

38 De Immort. An., c. XI. 

33 De Quant. An., c. XII. 

«> De Moribus Eccles. Cath., I., c. XXVII. 

" De Gen. ad.. Lit., c XII, 16. 

« De Quant. An., c. XVII, 50. 

« Op. cit., c. XX, 34. 

« Conf., X, 10. 

14 



THE SPECIES SENSIBILIS 15 

''Des qu'il se met a ecrire, saint Augustin enseigne la 
doctrine de Tinneite; et il s'y est toujours tenu."*^ 

St. Augustine 's appreciation of sensation is in perfect 
accord with his Platonic psychology. All truly wise men, 
he says, will hold more certainly to the testimony of the 
intellect than to that of the senses,^*' for the ''visio 
corporalis" which is synonomous with sensation, is de- 
pendent upon, and vastly inferior to the *'visio intellec- 
tualis. ' '*^ Whatever is known by the senses, if anything 
be known, ''et vile est, et satis est."*^ In one place*^ he 
even admits with the Academicians that whatever is per- 
ceived by the senses should be disregarded and consid- 
ered as nothing; for, as he proves at length,^° the senses 
cannot perceive truth. Acting in accordance with these 
sentiments, he treats of sensation only in disconnected 
paragraphs and incidental references. 

In the main, his theory of sensation is Neo-Platonic. 
Sensation, according to Plotinus, is the consciousness of 
bodily affections." St. Augustine, after a long discus- 
sion, decides : ' ' Sensus est passio corporis per se ipsam 
non latens animam.'"^- This ''passio corporis" arises, 
of course, from the action of an external material object. 
But it is a fundamental principle of St. Augustine, as of all 
Platonists, that the body can in no way affect or act upon 
the soul; how, then, does the soul become aware of the 
"passio corporis"! This St. Augustine explains in his 
"De Musica."®^ If the action of the external object is 
disagreeable to the body, the soul will with difficulty di- 
rect the impression into the channels of its own activity, 
"in sui operis itinera traducit." On account of this 



^ Saint Augustin, p. 51. 

« De Gen. ad Lit., c. XII, 24. 

« Ibid. 

« Soliloq., I., c. III. 

<» Cont. Acad., I., c. I, 3. 

«> De Div. Quaest. LXXXIII, IX. 

" Enneads, I., 4, 2. 

»2 De Quant. An., c. XXIII. 

M C. VI. 



16 THE SCHOLASTIC THEORY OF 

difificulty the soul becomes more attentive, becomes aware 
of its own action, and this is sensation. If, contrariwise, 
the action from without is pleasing to the body, the soul 
will readily convert this impression into its own activity. 
But of this action, too, the soul becomes aware, because it 
is out of the ordinary. 

The sense-organs, which are instruments or messen- 
gers of sensation,"^* are so modified, that in them the soul 
is more ready to act attentively upon the ''passiones cor- 
poris." There is light in the eye, air in the ear, vapor in 
the nose, humor in the mouth, and something of earth in 
the body. As soon as these are disturbed from without 
the soul becomes attentive and acts in harmony with the 
sense-organ, and this is sensation. "Ipsum sentire movere 
est corpus adversus ilium motum qui in eo f actus est." 
The one thought which recurs again and again is that in 
sensation the soul is not affected by the body, but that it 
acts upon the affections of the body. "Has operationes 
passionibus corporis puto animam exhibere cum sentit, 
non easdem passiones recipere." If the soul is affected 
at all ' ' a seipsa patitur, non a corpore. ' ' 

This whole line of thought St. Augustine borrows 
from Plotinus. But as Ott observes,^^ there is one impor- 
tant distinction : Plotinus accepts the doctrine of a world- 
soul which animates all matter. Hence he can logically 
speak of the body as being affected, as receiving impres- 
sions, in virtue of the world-soul. But St. Augiistine re- 
jects the world-soul. Hence the body cannot be affected, 
cannot be pleased or displeased, except in so far as it is 
animated by the human soul. But St. Augustine here 
speaks of body and soul, not as substantially united, 
but as distinct one from the other. Once the world-soul 
is rejected, the whole Neo-Platonic theory of sensation is 
without foundation. It is a purely stTbjective i:epresenta- 



w Cf. de Gen. ad Lit.. VH, 19. 
65 Philos. Jahrb., 1900. p. 45 ff. 



THE SPECIES SENSIBILIS 17 

tive view of sensation, which is well suited to the rest of 
Platonic psychology. 

Another Neo-Platonic doctrine which influences St. 
Augustine's theory of sensation is that of a medium be- 
tween body and soul. In one of his works he says : ' ' Inter 
corpus et animam, quod melius sit corpore, deterius ani- 
ma, non invenitur. "^'^ Nevertheless, he accepts as a gen- 
eral principle that the more subtle material bodies are 
nearer, or more akin, to a spirit, ' ' quamvis longe distante 
genere."" The body of man is largely of earth, still 
there is something of air contained in the lungs, which is 
sent out from the heart through the arteries. There is 
likewise something of fire having the qualities of warmth 
and light, which rises to the head. This is the source of 
the rays that spring forth from the eyes ; from this, too, 
rivulets, as it were, flow out to the ears, to the nose, to 
the palate, and even through the whole body. The light 
and warmth in the head is the immediate cause of sensa- 
tion. For hearing, the ''lux" is mixed with air, and for 
smell, with vapor; the humid is mixed with the ''lux" 
for taste, and earth for touch. °® Because fire and light 
are nearest to the incorporeal substances, the soul acts 
immediately on these and through these, on other parts of 
the body f^ " Anima tamen cui sentiendi vis inest, cum cor- 
porea non sit, per subtilius corpus agitat vigorem sen- 
tiendi. Inchoat itaque motum in omnibus sensibus a sub- 
tilitate ignis. ""^^ "NuUus enim sine his duobus vel sensus 
in corpore est."*^^ 

But St. Augustine is not influenced by Plotinus alone ; 
indeed, he introduces some thoughts into his theory of 
sensation which are quite foreign to Neo-Platonism. This 
reminds us of the fact that St. Augustine is an eclectic : he 



se De Div. Quaes. LXXXIII, LIX. 
57 De Gen. ad Lit., c. Ill, 4. 

«8Ibid. 

59 Op. cit., c. VII, 15. 
6° Op. cit., c. Ill, 5. 
«i Op. cit., c. Ill, 4. 



18 THE SCHOLASTIC THEORY OF 

borrows from various philosopliical systems without com- 
pletely unifying the different elements into one grand 
synthesis."^ 

In his De Trinitate, Lib. XI., c.2, we read : * ' Cum igitur I 
aliquod corpus videmus, haec tria, quod facillimum est, ' 
consideranda sunt et dignoscenda. Primo ipsa res quam 
videmus, sive lapidem, sive aliquam flammam, sive quid 
aliud quod videri oculis potest; quod utique jam esse 
poterat, et antequam videretur; deinde, visio, quae non 
erat priusquam rem illam objectatur sensui sentiremus; 
tertio, quod in ea re quae videtur, quamdiu videtur sen- 
sum detinet oculorum, id est, animi intentio. In his igitur 
tribus, non solum est manifesta distinctio, sed etiam dis- 
ereta natura. Primum quippe illud corpus sensibile longe 
alterius naturae est, quam sensus oculorum, quo sibimet 
incidente fit visio. Ipsaque visio quid aliud, quam sensus 
ex ea re quae sentitur informatus apparet? Quamvis 
re visibili detracta nulla sit, nee ulla omnino esse possit 
talis visio, si corpus non sit quod videri queat : nuUo modo 
tamen ejusdem substantiae est corpus quo formatur sen- 
sus oculorum, cum idem corpus videtur, et ipsa forma 
quae ab eodem imprimitur sensus, quae visio vocatur. Cor- 
pus enim visum in sua natura separabile est : sensus autem 
erat in animante, etiam priusquam videret quod videre 
posset, cum in aliquid visibile incurreret, vel visio quae fit 
in sensu ex visibili corpore, cum jam cognitum est et 
videtur ; sensus ergo vel visio, id est sensus f ormatus ex- 
trinsecus, ad animantis naturam pertinet, omnino aliam 
quam est illud corpus quod videndo sentimus, quo sen- 
sus non ita formatur ut sensus sit, sed ut visio sit. Nam 
sensus est ante objectum rei sensibilis ; nisi esset in nobis, 
non distaremus a caecis, dum nihil videmus, sive in tene 
bris, sive clausis luminibus. Hoe autem distamus quod 
nobis inest et non videntibus, quo videre possimus, qui 
sensus vocatur ; illis vero non inest ; nee aliunde nisi quod 



«2 Cf. Ueberweg, II, p. 126. 



THE SPECIES SENSIBILIS 19 

eo carent, caeci appellantur. Itemque ilia animi inten- 
tio, quae in ea re quam videmus sensum tenet, atque 
utrumque conjungit, non tantum ab ea re visibili natura 
differt; quandoquidem iste animus illud corpus est; sed 
ab ipso quoque sensu atque visione; quoniam solius animi 
est haec intentio; sensus autem oculorum non ob aliud 
sensus corporis dicitur, nisi quia et ipsi oculi membra 
sunt corporis; et quamvis non sentiat corpus exanime, 
anima tamen commixta corpori per instrumentum sentit 
corporeum, et idem instrumentum sensus vocatur. . . . 
Haec igitur tria, corpus quod videtur, et ipsa visio, et 
quae utrumque conjungit intentio, manifesta sunt ad 
dignoscendum, non solum propria singulorum, verum 
etiam propter clifferentiam naturarum. 

Atque in his cum sensus non procedat ex corpore illo 
quod videtur, sed ex corpore sentientis animantis, cui 
anima suo quodam miro modo contemperatur ; tamen ex 
corpore quod videtur gignitur visio, id est sensus ipse 
formatur ; ut jam non tantum sensus qui etiam in tenebris 
esse integer potest, dum est incolumitas oculorum, sed 
etiam sensus informatus sit, quae visio vocatur. Gignitur 
ergo ex re visibili visio, sed non ex sola, nisi adsit et 
videns. Quocirca ex visibili et vidente gignitur visio, ita 
sane ut ex vidente sensus oculorum, et aspicientis atque 
intuentis intentio; ilia tamen informatio sensus, quae 
visio dicitur, a solo imprimatur corpore quod videtur, id 
est, a re aliqua visibili ; qua detracta, nulla remanet forma 
quae inerat sensui, dum adesset illud quo videbatur; 
sensus tamen ipse remanet qui erat et priusquam aliquid 
sentiretur ; velut in aqua vestigium tamdiu est, donee ip- 
sum corpus quod imprimitur inest; quo ablato nullum 
erit, cum remaneat aqua, quae erat et antequam illam 
formam corporis caperet. Ideoque non possumus quidem 
dicere quod sensum gignat res visibilis; gignit tamen 
formam velut similitudinem suam, quae fit in sensu, cum 
aliquid videndo sentimus. Sed formam corporis quod 



20 THE SCHOLASTIC THEORY OF 

videmus, et formam quae ab ilia in sensu videntis fit, per 
eumdem sensum non discernimus ; quoniam tanta con- 
junctio est, ut non pateat discernendi locus. Sed ratione 
colligimus nequaquam nos potuisse sentire, nisi fieret in 
sensu nostro aliqua similitudo eonspecti corporis. Neque 
enim cum annulus cerae imprimitur, ideo nulla imago 
facta est, quia non discernitur, nisi cum fuerit separata. 
Sed quoniam post ceram separatam manet quod factum 
est ut videri possit, propterea facile persuadetur, quod 
inerat jam cerae forma impressa ex annulo et antequam 
ab ilia separaretur. Si autem liquido humori adjung- 
eretur annulus, eo detracto nihil imaginis appararet: 
nee ideo tamen discernere ratio non deberet, fuisse in 
illo humore, antequam detraheretur annuli formam fac- 
tam ex annulo, quae distinguenda est ab ea forma quae in 
annulo est, unde ista facta est quae detracto annulo non 
erit, quamvis ilia in annulo maneat unde ista facta est. 

Sic sensus oculorum non ideo non babet imaginem 
corporis quod videtur, quia eo detracto non remanet, ac 
per hoc tardioribus ingeniis difficillime persuaderi potest, 
formari in sensu nostro imaginem rei visibilis, cum eam 
videmus, et eamdem formam esse visionem, " 

Does not this passage call to mind the elSos-theory of 
Aristotle? It is true, neither Ott in his series of articles, 
nor Martin when treating of St. Augustine's theory of 
sensation, refer to this passage. Even Siebeck, who seems 
so anxious to accuse the Scholastics of corrupting Aris- 
totle's elSos-theory, says nothing of this passage. Hence 
I have quoted it in extenso that the author's meaning 
might appear from the context. It is very clear that 
St. Augustine is speaking of the origin of vision, which 
he ascribes to three factors : the object, the sense, and the 
''intentio animi." The object, of course, is any material 
being having light or color. 

What is the ''sensus" of which he speaks? Is it 
merely the material organ of the body, the eye? In the 
first place, the "sensus" belongs "ad auimantis natur- 



THE SPECIES SENSIBILIS 21 

am"; a '' corpus exanime" has no sensation; the sense 
proceeds '^ex corpore sentientis animantis." Hence it 
is at least an animated organ. But it is more than that ; 
it is the organ plus something else. St. Augustine calls 
it ' ' sensus oculorum ' ' ; therefore it is something distinct, 
though not separate, from the eye. It is called "^^ sensus 
corporis, ' ' because the eye is a member of the body ; con- 
sequently, strictly speaking, the sense does not pertain 
to the body. It differs from the ' ' intentio, ' ' because this 
pertains to the soul alone ; hence, by inference, the sense 
pertains in part to the soul, in part to the body. Finally, 
the ' ' sensus " is a power ' ' quo videre possimus, ' ' in virtue 
of which we differ from the blind even when we are not 
actually seeing. 

This meaning of ''sensus" appears also in other 
works of St. Augustine. The sense is a faculty of the soul 
which is exercised through the body, but it is not a faculty 
of the body.''^ Indeed, we hear by means of our ears, but 
our ears do not hear; ''alius est intus qui audit per 
aurem;"®* "non ergo oculi vident, sed quidam per oculos 
videt."^^ 

The importance of this inquiry concerning the mean- 
ing of ' ' sensus ' ' is brought home by such expressions as 
"ipsaque visio, quid aliud quam sensus ex ea re quae 
sentitur informatus apparet!" If, then, by "sensus" 
St. AugTistine meant the material organ, we should have 
to conclude that, to his mind, sensation, or vision, is sim- 
ply the ' ' inf ormatio, " so to say, of this organ, the effect of 
physical or chemical accidents of the object on the organ. 
But since, as we have seen, the "sensus" is more than 
the mere organ, the ' ' informatio, ' ' too, is more than the 
mere physical or chemical impression. 

By ' ' inf ormatio ' ' St. Augustine means : ' ' Ipsa forma 
. . . ab eodem (objecto) imprimitur sensui." What, 



" De Gen. ad Lit., c. Ill, 5. 

« Serm., LII, 7. 

«» Op. cit., CXXVI, 2. 



22 THE SCHOLASTIC THEORY OF 

then, is this "forma quae inerat sensni?" In the first 
place, this form in the sense is not of the same nature 
as the object which is seen. It arises from the object, 
''a solo imprimatur corpore quod videtur," just as a 
reflection in water arises from an object. So, too, it is a 
likeness of the object, "velut similitudinem suam." In 
another passage of the same chapter he calls it "'imago 
simillima rei ejus quam cernimus." The "species cor- 
poris" is seen, and the image of this species is in the 
sense. 

Reason tells us that we have no sensation unless some 
likeness of the object be in our sense. Just as a ring, 
immersed in a liquid, must give to this liquid a form 
which is similar to its own form but not identical with it, 
so, too, in sensation an impression of forms must take j 
place. 

This "informatio sensus" is sensation. Without it 
sensation is not possible. Must we then infer that the 
"object acts upon the sense, and that thus matter affects 
spirit? We have seen, according to St. Augustine, that 
the body does not act upon the soul, because the body, 
being material, is of a lower order of being than the 
soul. "Omni enim modo praestantior est qui facit, ea re 
de qua aliquid facit; neque ullo modo spirits praestantius 
est corpus; imo perspicuo modo spiritus corpore."^" Con- 
sequently neither can a material object in any way act 
upon the sense, which is a faculty of the soul. This image 
or likeness of the object in the sense is of a higher order 
of being than the object itself, and hence, is not produced 
by the object, but "ipse spiritus in seipso facit (cor- 
poris imaginem)"" The spirit continually forms in 
itself an image of the object perceived.*^^^ 

St. Augustine regards the sense as an active faculty. 
In vision the sense goes out to the object; "Is (visus) 



6« De Gen. ad Lit., c. XH, 16. 
•' Ibid. 
«'a Ibid. 



THE SPECIES SENSIBILIS 23 

enim se foras porrigit."^^ Vision takes place when the 
"sensus oculorum" strikes upon an object. °*' The objects 
of the other senses come to the organ of sense : ' ' In aures 
inflnit sonus, aut naribus exhalationes, palato sapores, 
caetero corpori qualibet solida et corpulenta admoventur 
extrinsecus. "'° But even here the sense is active; e. g., 
when the air in the ear is set in motion by the movement 
of air outside the ear, that is, by sound, the soul does 
not lose control over the movement of the "aer serenis- 
simus" in the ear. But St. Augustine concedes that the 
soul moves this "aer serenissimus" in a different manner 
before the sound strikes the ear, than after.'^ In either 
case, however, the sense is active, actuated not by the 
object, but "intentione facientis." 

On the other hand, we read in the passage from the 
"De Trinitate" quoted above: ''Informatio sensus . . . 
a solo imprimatur corpore quod videtur, id est, a re 
aliqua visibili, qua detracta, nulla remanet forma quae 
inerat sensui, dum adesset illud quod videbatur;" and 
further on in the same chapter: "Ut manifestum sit, 
banc affectionem nostro sensui ex ea re quae videbatur 
impressam." How can these statements, seemingly so 
contradictory to the above expressions regarding the 
activity of the sense, be intelligently explained? 

The general principle of St. Augustine's theory of 
sensation must stand: the sense is active, is the active 
cause of the "forma quae inerat sensui." But this does 
not exclude any and every influence of the object. The 
sense of itself is indifferent. Though active, it must be 
determined to form in itself a specific image, and this is 
the role of the object. In other words, the image arises 
out of the object, the object offers the material out of 
which the sense forms the image. The object is the 



68 De Quant. An., c. XXIII. 
'* De Trinit., ut supra. 
■"> De Mus.. c. VI, 5. 
" Ibid. 



24 THE SCHOLASTIC THEORY OF 

passive or material cause of the image, whereas the 
sense is the active efficient cause. 

As an active faculty, the sense is actuated ah intrinseco, 
i.e., by the "animi intentio, quae in ea re quam videmus 
sensum tenet, atque utrumque (object and sense) con- 
jungit." This 'intentio" pertains to the soul alone, 
''quia voluntas est." Its function is "ut et sensum for- 
mandum admoveat ei rei quae cernitur, et in ea forma- 
tum teneat." Consequently this is really the most im- 
portant factor in the origin of sensation. If, finally, we 
inquire what determines the * ' intentio animi, ' ' St. Augus- 
tine refers us to the will of God, the immutable designs 
of God's wisdom. '^- 

Though the species or image in the sense arises out 
of a material object, it is not material. It is a "species 
sine tumore molis, sine strepitu vocis, sine spatio vel 
loci, vel temporis.'"^ In the same moment when a ma- 
terial object is touched by a sense, there appears in the 
soul, not a body, but something similar to a body;^* — 
similar, because it represents the material conditions 
of the object. Just as water receives the form of an 
object, so likewise does the sense; and as a reflection 
in water represents the material conditions of the object, 
so also the image in the sense is a likeness of the object 
as it exists in matter. It is a "forma quae ab ilia (forma 
corporis) in sensu fit." Like the form of a ring in a 
liquid, it is the image of the "species corporis." "Nullo 
modo . . . ejusdem substantiae est corpus quo forma- 
tur sensus oculorum . . . et ipsa forma quae ab 
eodem imprimitur sensui. ' '" 

Finally, it must be observed that St. Augustine does 
not regard this image or species as the immediate object 
of sensation. As the Scholastics say, it is not the "prin- 



« De Trinit., lib. Ill, c. 2; cf. Op. cit. 
" De Civit. Dei, lib. VIII, c. 6. 
'^ De Gen. ad Lit., c. XII. 24. 
^* De Trinit., ut supra. 



THE SPECIES SENSIBILIS 25 

cipium quod cognitionis, " but rather the ' ' principium 
quo." By means of this image we see, not the image, 
but the object itself. The sense itself, says St. Augustine, 
does not distinguish between the natural form of the 
object and the form which is in the sense. By reason 
alone do we postulate the existence of this form in the 
sense f^ in fact, we are not conscious of the image in the 
sense until, by an act of the will, we turn our attention 
away from the object and reflect on the mental process." 
To sum up, according to St. Augustine, we cannot 
know by our senses, cannot have sensation, unless an 
image of the object be in the sense. This image, formed 
in the sense by the spirit and out of the object, is an im- 
material representation or likeness of the object. Its 
function is to unite the subject and object of sensation, 
and to direct or to determine the sense-faculty, but not 
to actuate it. How it originates, St. Augustine does not 
state, except that it results from the action of the sense 
on the object of sense. St. Augustine sometimes calls 
it ''species" or "forma," but more commonly, "imago" 
or " similitudo. " 

8C0TUS ERIUGENA.—Tlie age of St. Augustine 
was followed by a woeful dearth of Christian learning. 
After the devastating hordes of barbarians had overrun 
Europe, Christianity faced the problem of creating a 
new civilization — a problem not of years and decades, 
but of centuries. The most imperative need of these 
centuries was the preservation of the past lore. Hence 
we have the encyclopedic compilations of Cassiodorus, 
of Venerable Bede, of Isidore of Seville, of Rabanus 
Maurus, and others. Their express purpose was the 
presentation of traditional doctrines, regardless of their 
own opinions. Whenever they treat of philosophy, St. 



7« De Trinit., XI, c. 2. 

" De Gen. ad Lit., c. XII. 11. 



26 THE SCHOLASTIC THEORY OF 

Augustine is their final authority; as Cassiodorus 
writes: ''Hoc enim Pater sentit Augustinus. ' "^ 

The instruction of the populace was another urgent 
demand of the times. This led to the compilation of 
short dogmatic manuals and popular treatises in which 
disputed questions and speculative discussions gave way 
to practical suggestions. In psychology, the irepl (pweus 
av^puTTov of Nemesius of Edessa, a contemporary of St. 
Augustine, served as a model for these manuals. This 
work of Nemesius has been styled the first systematic 
treatise on anthropology.^^ Other works of this period 
dealing with the origin and nature of the soul, its virtues 
and vices, are directive rather than speculative, as, for 
instance, the ' ' De Statu Animae ' ' of Claudianus Mamer- 
tus and the "De Eatione Animae" of Alcuin. In his 
''De Fide Orthodoxa" (C. XII, sq.), St. John Damascene 
presents a "psychology in nuce" borrowed largely from 
Nemesius. So dependent is he when he speaks of sen- 
sation, as to reiterate even the trivial observation of 
Nemesius that, of all animals having ears, man and ape 
alone cannot move them. The problem of sensation was, 
at best, dealt with quite summarily. Rabanus Maurus, 
"the leading representative of this encyclopedic litera- 
ture in philosophy,"*'' begins the last chapter of his "De 
Anima" with the words : "Nunc restat ut de officiis quin- 
que sensuum pauca dicantur."®^ And these few words 
are borrowed from St. Augustine. 

As a further index of the regard, or disregard, with 
which these early middle ages viewed psychology, it 
may be noted that the manuals of psychology became 
shorter and shorter. Finally Ermanricus of EUwangen, 
a pupil of Rabanus, reduced all knowledge about tlie 
soul, which he considered worth knowing, to three chap- 
ters, one from Isidore of Seville, another from Alcuin, 



's De An., c. i). 

" Cf . De Wulf, Hist, of Med. Philos., p. 08. 

8" Ibid., p. 126. 

»i C. XII. 



THE SPECIES SENSIBILIS 27 

and a third from Gennadius ; and these are largely moral, 
not speeulative.^- 

In the ninth century we find the first system of con- 
structive thought since St. Augustine. The study of 
ancient Greek philosophy, a wealth of imagination, and 
a comprehensive synthetic mind lifted Scotus Eriugena 
above the commentators and compilers of his, and of 
earlier centuries.®^ Alcuin in the eighth century apolo- 
gized when he introduced dialectics into theology; 
Scotus Eriugena boldly attempted a rational synthesis 
of all knowledge, human and divine. Whether we accept 
little of his philosophy or none at all, we still owe him 
the credit of reintroducing independent philosophical 
speculation. 

The philosophy of Scotus is, in the main, Neo- 
Platonic. Some Aristotelian principles appear in his 
works, but even these are tinged with emanationism which 
permeates the whole system of thought. Psychology is 
far from holding a central place in his scheme of knowl- 
edge. ^'Majus enim est quod definit quam quod defini- 
tur."^* Hence the soul cannot fully know its own essence 
and constitution. What psychology he does give us, is 
plainly inspired by Plato, the "philosophorum sum- 
mus."*^ For instance, he speaks of the soul as a simple 
and individual nature and as the real ego,^'' the body 
being a part of the ego only in so far as it is possessed 
by the soul.^^ The soul is the principle of activity in the 
body, indeed, it creates its own body.^^ The action of 
the soul on the body is mediated by a finer substance 
which is similar to light and air.®^ This last doctrine he 
owes to Plotinus or to St. Augustine. 



82 Werner, Denkschr. d. Wiener- Akad., Vol. 25, p. 80. 

83 Cf. Turner, Op. cit., p. 256. 
^ De Divis. Nat., I, 43. 

85 Op. cit.. Ill, 36. 

86 Op. cit., II, 23. 
8' Op. cit., I, 54. 
88 Op. cit., II, 24. 
8» Op. cit.. Ill, 36. 



28 THE SCHOLASTIC THEORY OF 

In his theory of knowledge, too, Scotus is plainly Neo- 
Platonic. There are in man two cognitive faculties : the 
higher, to which belong intellect, reason, and the interior 
sense {biavoia) ; and the lower, which is the external sense 
(aia^rjaLs). The intellect is the power of contemplation 
and has God for its object; the object of reason is the 
primordial causes of things; by our internal sense we 
know the nature and interrelation of phenomenal things."" 
Hence we must conclude that by our external sense we 
perceive merely the appearances, the phenomena of the 
external world''^ 

In one place^^ we are informed that all knowledge 
begins with sense-experience; that by abstraction we 
rise from sense-knowledge to contemplation. However, 
this ascending knowledge is only preparatory to the 
knowledge that avails most, the knowledge descending 
from God to primordial causes, to the nature and essence 
of things, to sensible nature. Even apart from this 
rather disparaging account of the role of sensation, 
Scotus' method is so strikingly analytic and deductive 
as to warrant the conclusion that, in his mind, sensation 
is of little importance as a faculty of knowlege. In fact, 
no other view of sensation is compatible with Neo-Pla- 
tonic psychology. 

We can, then, hardly expect a complete systematic 
theory of sensation from him. Scotus does tell us^^ that 
the sense is a simple and uniform faculty of the soul, 
having five corporeal instruments or organs. Though 
belonging to the soul rather than to the body, the sense 
does not form an essential part of the soul. It is a 
messenger, an " internuncius, " between the soul and the 
body, or ''conjunctio quaedam est animae et corporis." 

What interests us more directly, is the fact that Scotus 



80 Op. cit., II, 23. 

91 Cf. Stockl, Gesch. d. Philos. d. Mittelalt., I. p. 7£ 

92 Op. cit., II, 23. 

93 Op. cit., II, 23. 



THE SPECIES SENSIBILIS 29 

alludes to St. Augustine's theory of sense-images. He 
says of the external sense: "Quod per quinquepertitum 
corporis instrumentum, veluti per quasdam cujusdam 
civitatis quinque portas, sensibilium rerum similitudines 
ex qualitatibus et quantatibus exterioris mundi venientes, 
ceterisque, quibus sensus exterior formatur, interius 
recipiat, et veluti ostiarius quidam internuntiusque ea, 
quae extrinsecus introducit, praesidenti interior! sensui, 
annunciet. "^* The likenesses, then, of objects are received 
by the external senses. These likenesses are something 
distinct from the impressions in the sense-organs, because 
the sense receives likenesses through the sense-organ. 
They are not the result of the physical or chemical changes 
in the organ of sense, since they are received through 
the organs as through so many gates. Hence the organs 
of sense do not contribute to the formation of the like- 
nesses, but serve merely as passageways. In another 
passage of this same chapter he speaks of the soul as 
receiving the "phantasias ipsarum rerum per exteriorem 
sensum." Since the sense as a faculty of the soul, or the 
soul itself, receives these "similitudines" or "phan- 
tasias," they must be in some way immaterial; quid- 
quid recipitur, recipitur secundum modum recipientis. 
If, then, Scotus says in this same paragraph: "Et ilia 
prior (imago in sensibus expressa) corpori semper ad- 
haeret," this does not imply that the "imago" is ma- 
terial. Of the sense itself, which is physical rather than 
corporeal, he says: "Sine corpore eo nee utitur, nee uti 
potest."^' Indeed, it cannot be disputed that Scotus 
regards the body as a necessary condition for the origin 
of sense-images ; but to say that, therefore, he considers 
the image corporeal would be an unwarranted conclusion. 
Another fact to be observed is that, according to 
Scotus, the "similitudines" come "ex qualitatibus, etc." 
St. Augustine had held that the images arise out of the 



9« Ibid. 

"5 Op. cit., II, 23. 



30 THE SCHOLASTIC THEORY OF 

object and that the sense is informed by the object. 
Scotiis is somewhat more specific. He maintains that the 
images come from the qualities, quantities, and other acci- 
dents of the object, and that these accidents inform the 
sense. This substantiates the inference drawn above that, 
according to Scotus, by our external senses we can only 
know the phenonema of things. 

The '''■ex qualitatibus, etc.," is significant. It shows 
that Scotus, like St. Augustine, regarded the object as 
the material cause out of which the sense-images are 
formed. In another place he clearly states that the sense 
itself is the active cause. ''Extenditur enim visus ad 
recipiendas visibilium rerum colorabiles species ; extendi- 
tur auditus ad vocum sen aliorum sonituum, percussione 
aeris erumpentium, prosodias, quas formas coloresque 
vocum dicimus in se imaginandas. "^"^ The forms and 
species of external objects are pictured or imaged in 
the sense by the sense; they are taken from the objects 
by the sense. Consequently, according to Scotus, the 
union between the object and the subject of sensation is 
due, not to any action on the part of the object, but to 
the activity of the sense, which goes out to the object. 
St. Augustine held the same view regarding vision; 
Scotus, more consistently, applies it also to hearing and 
perhaps even to smell; for, he says: "Ceteri enim tres 
sensus intra terminos corporis contineri videntur, quam- 
vis olfaciendi sensus foris protendi non incongrue, ut 
arbitror, existimetur. ' '^^ 

It is the function of the image to determine the sense 
and to unite the object and the subject. We read: *'Ter- 
tius motus est compositus, per quern, quae extra sunt, 
anima tangens, veluti ex quibusdam signis apud seipsam 
visibilium rationes reformat . . . Deinde per ipsas 
(phantasias) ad rationes earum, quarum phantasiae sunt, 
perveniens, intra seipsam eas rationes dico, tractat atque 



9« Op. cit., Ill, 36. 
«' Ibid. 



J 



THE SPECIES SENSIBILIS 31 

conf ormat. ' "® These words would seem to define the 
' * phantasiae " as intermediaries from which we infer the 
knowledge of external things. But remembering that 
Scotus looks upon the phenomena of things as the sole 
object of sensation, we must interpret the above words 
as meaning that, through the phenomena perceived by 
the sense, the soul arrives at the knowledge of the nature 
of things, ''rationes reformat," *^ad rationes earum 
. . . perveniens." Scotus does regard sense-knowledge 
as a means or stepping-stone to higher knowledge, and 
consequently, in a sense, intermediary. Thus he says 
that the interior sense, the ^'tertius motus," begins "ex 
phantasiis rerum exteriorum per exteriorem sensum sibi 
nunciatis. "^^ Nevertheless, the "imago in sensibus ex- 
pressa . . . quamvis in sensu sit, seipsam non 
sentit.'"«° 

In some particulars this theory of Scotus is more spe- 
cific than that of St. Augustine, as was indicated. In so 
far it shows a development. On the other hand, many 
details are here omitted, which St. Augustine had dis- 
cussed at length. The general tendency is the same ; the 
activity of the sense is emphasized, that of the object 
is regarded as minimal. Scotus applies to the species 
all the names used by St. Augustine, and adds one more, 
taken from the Greek, viz., "phantasia." 

ST. ANSELM. — It is not surprising that St. Anselm, 
the Father of Scholasticism, accepts the psychical aspect 
of the species sensibilis, since he refers to St. Augustine 
on nearly every page of his writings. This dependence 
appears at first sight in the isolated problems of psy- 
chology which St. Anselm discusses. Man is constituted 
of body and soul, "ex natura animae et ex natura cor- 



98 Op. cit., II, 23. 
<« Ibid. 
iflo Ibid. 



32 THE SCHOLASTIC THEORY OF 



mortale. "^"^ At the time of St. Anselm, as we shall see 
in the next chapter, form was defined as a distinct prop- 
erty or quality of an object. Either because he himself 
accepted this view of his contemporaries, or to avoid 
being misunderstood by them, St. Anselm does not apply 
the doctrine of matter and form to the union of body 
and soul in man.^°^ He defends the unity of body and 
soul more in the sense of Plato:"* the soul is the causa 
efficiens of all activity in the body; it is the spontaneous 
active principle."^ The body belongs to the essence of 
man only as a necessary tool or instrument of the soul. 

St. Anselm 's view of sensation, even as his psychology 
in general, calls to mind the doctrine of the Bishop of 
Hippo. He nowhere formulates a systematic theory ot 
sensation ; even his allusions to this problem are few and 
incidental. The theory of intellectual knowledge is de- 
veloped far more completely."" Herein he is logical, 
because he says truth is the object of the intellect, not 
of the senses;"^ introspection is more important than 
observation."^ Nevertheless he contends that sensation 
is a conditio sine qua non for the knowledge of ma- 
terial extended objects."® By means of the memory 
the senses furnish the material of thought."" Sensation, 
then, is an activity of the soul whereby we come to the 
knowledge of external bodies; ''sola corporea sunt sensi- 
bilia, quia sensus circa corpus et in corpore sunt.""^ 

Sensation is an activity of the soul, ''anima sentit.""- 
But since the soul is immaterial, it must make use of 



"» Meditat., c. 19. 
»"* De Graram., c. 8. 

103 Cf. De Verges, St. Anselm, p. 193. 

104 Q{^ Fischer, Die Erkenntnissl. Ansel ms, p. 5. 
»<» Prosl., c. 13. 

>o« De Vorges, op. cit.. p. 88flF. 

»•" De Verit., c. 6. 

108 Cf. Monol., c. 46. 

»«» De Lib. Arbit.. o. 3. 

»o Monol., c. 47. 

»i Prosl,, c. 6. 

•« Ibid. 



THE SPECIES SENSIBILIS 33 

material means in order to know material objects. These 
means or conditions of sensation are the organs of 
sense."^ Hence we have sensation ''per corpus." ''Qui 
enim sentit, cognoscit secundum sensuum proprietatem 
ut per visum colores, per gustum sapores.""* 

Domet de Vorges says of St. Anselm: "Ni pour la 
sensation ni pour 1 'intelligence, il ne donne une theorie 
de la perception. "^^^ We shall therefore search his 
works in vain for a development of the species-theory. 
iWe find evident traces of this theory as presented by St. 
Augustine, but little more. Since, however, several 
passages from the "Monologium" are commonly con- 
nected with the Scholastic theory of the species sensibilis, 
because of a false interpretation placed upon them, it 
will not be out of place to discuss St. Anselm 's view of 
this theory, as far as we can gather it from incidental 
allusions. 

In the De Veritate, c. 6, St. Anselm thus describes 
a phenomenon of sight: "Cum visus transit per corpus 
aliquod aerei coloris, non aliter impeditur assumere 
similitudinem coloris, quem ultra videt, quam cum tran- 
sit per aera. . . . Quapropter, quoniam post unum accept- 
um colorem, secundum quod illo affectus est, alium, qui- 
cumque occurrat, aut nullatenus, aut minus integre susci- 
pit; ideo, ilium, quem prius cepit, aut solum, aut cum eo 
qui post occurrit, renuntiat. Si enim visus, quantum 
capax est coloris, tantum afficitur priore colore, non potest 
alium sentire simul colorem; si autem minus quam 
colorem sentire possit priore afficitur, potest alium 
sentire. ' ' 

The activity of the sense is here emphasized, as it is 
in St. Augustine; "visus transit per corpus, etc." What 
is more important, St. Anselm here distinguishes between 
colore affici, colorem accipere, suscipere, capere, shnilitu- 

"3 Meditat., c. 19. 

1" Prosl., c. 6. 

"5 Op. cit., p. 111. 



34 THE SCHOLASTIC THEORY OF 

dinem colons assumere on the one hand, and sentire 
colorem on the other. The first group of expressions 
refer to the material impression of color on the lens of 
the eye. Remembering that St. Anselm is a Platonist or 
Augustinian in psychology, he would never say that the 
sense of sight as a faculty of the soul is affected by color. 
Nor would he say that the sense-faculty receives color, 
not even that it assumes the likeness of color. All this is 
true enough of the physical organ of sight, but not of the 
immaterial faculty or sense. Besides, the '^visus" in this 
meaning, being limited, is capable of receiving only a 
definite amount of color. Certainly this does not apply 
to the faculty of sight. As Fischer points out,"*^ St. 
Anselm distinguishes two elements in sensation, the phys- 
ical element, which is the material impression on the 
sense-organ, and the psychical element, expressed above 
by the ''sentire colorem," by which the soul knows the 
object which causes the affection of the sense-organ. 

The texts which are falsely adduced as revealing St. 
Anselm 's position regarding the species sensibilis are 
taken from the ' ' Monologium. " There we read: "Cum 
cogito notum mihi hominem absentem, formatur acies 
cogitationis meae in talem imaginem ejus qualem illam 
per visum ocularem attraxi."^^^ In another passage we j 
read: "Sed in hominis cogitatione cum cogitat aliquid 
quod extra ejus mentem est, nonnasciturverbumcogitatae 
rei ex ipsa re, quia ipsa, absens est a cogitationis intuitu, 
sed ex rei aliqua similitudine vel imagine quae est in 
cogitantis memoria, aut forte quae tunc cum cogitat per 
corporeum sensum ex re praesenti in mentem attrahi- 
tur.""« 

From these texts, Reid^^^ was the first to conclude that 
St. Anselm defended the species as intermediaries, as 
the objechmi quod cognitionis and not the objectum quo; 



»« Op. cit., p. 21. 
1" Monol., c. 33. 
"8 Op. cit., c. 62. 
"» Essays on the Intellectual Powers, II, 8. 



THE SPECIES SENSIBILIS 35 

in other words, that St. Anselm defended the representa- 
tive or mediate view of sensation, Haureau^^" united 
with the founder of the Scottish school in this contention. 
Now, in both texts, St. Anselm evidently speaks of the 
formation of a concept, of ''cogitatio," not of sensation. 
He sees an analogy between the generation of the Divine 
Word and the formation of a concept.^^^ The theory of 
intermediate images, however, is a theory of sensation. 
Whether in thought the mind is directed to the object 
itself or to an image of the object brought to the mind 
by the external senses, this has little influence on the 
theory of sensation. 

Besides, the passages are too incomplete and too in- 
definite to show us the exact thought of St. Anselm. 
The words, "nascitur verbum cogitatae rei . . . ex 
rei aliqua similitudine, etc.," might mean that the sense- 
image is an intermediary which we see directly, and that, 
by inference only, we conclude to an external object ; but 
they may equally as well mean that the sense-image is 
a means in which we see the object immediately. But 
since our opponents claim that this theory of St. Anselm 
became more explicit in later Scholastics, we are justified 
in suspending our judgment, and interpreting these vague 
passages in the light of later Scholastics. And there, as 
we shall see, the doctrine of intermediate images is most 
emphatically and explicitly rejected. If, on the other 
hand, we interpret these passages in accordance with 
the explicit teaching of St. Anselm 's great authority and 
guide, St. Augustine, then, too, we must reject the inter- 
pretation of Reid and Haureau. 

Finally, granting that the passages are vague and 
incomplete, they hint at the doctrine of immediate per- 
ception rather than at the opposite view. Thought is 
based on the sense-image ; but the image is not the object 



1™ Hist, de la Philos. scol., I, p. 270. 
'*' De Vorges, op. cit., p. III. 



36 THE SCHOLASTIC THEORY OF 

of thought: ''Nascitur verbum cogitatae rei" and not the 
' ' verbum ' ' of the image. 

All the distinctive features of the psychical aspect 
of the species sensibilis flow directly from Platonic 
psychology and epistemology. If the soul is the principle 
of all activity and the body is merely the tool or the 
instrument of the soul ; if matter can in no way act upon 
spirit, if all knowledge is innate and learning is a pro- 
cess of remembering; — then the psychical aspect of the 
species sensibilis is the only logical one ; then the sense 
itself is the active efficient cause of the species sensibilis. 
The object can, at most, direct or determine this activity 
of the sense which arises ah intrinseco and not ah 
extrinseco, i. e., the sense is an active faculty. Then, 
too, the species sensibilis is evidently immaterial, since it 
is produced by the psychical faculty as a determination 
of this same faculty. 

Again it follows from Platonic psychology that the 
physical and physiological factors accompanying sensa- 
tion are of little consequence. These are in no sense 
causal; they are merely so many phenomena that occa- 
sion the origin of sensation. The influence of the object 
is minimal. Hence introspection and deduction are more 
fruitful sources of knowledge than observation and in- 
duction. *'Noli foras ire, in te redi, in interiore homine 
habitat Veritas. "^^- Mysticism, then, is preferable to 
science, and sensation, a lowly means of knowledge, is 
scarcely deserving of systematic study. 

It must not, then, be imagined that the psychical aspect 
of the species sensibilis ceased with St. Anselm. When- 
ever psychology is purely Platonic, then the view of the 
species sensibilis is purely psychical. Thus in the thir- 
teenth century, Matthew of Aquasparta, a disciple of 
St. Bonaventure, presented a theory of sensation which 
is as purely psychical as is that of St. Augustine.^^"* 



^^ St. Augustine, De Vera Relig., c. 
»23 Cf. De Wulf. op. cit., p. 291. 



THE SPECIES SENSIBILIS 37 

When, however, Arabian and Aristotelian elements 
are introduced into Platonic psychology, then, too, the 
aspect of the species sensibilis becomes less distinctly 
psychical ; it assumes new characteristics without entirely 
putting off the old. This struggle between opposing tend- 
encies regarding the species-theory will claim oTir atten- 
tion in the next chapter. 



CHAPTER II. 
THE MATERIALISTIC ASPECT 

OF THE 

SPECIES SENSIBILIS. 

ARABIAN PHILOSOPHY. — Arahian philosophy 
comes into prominence about the ninth century, when the 
treasures of Greek thought were translated by the Syri- 
ans/^* The Arabians of that day were an active, hearty 
people, striving to conquer the world and to control the 
forces of nature. Devoted to science even more than to 
philosophy, they were preeminent in astronomy, mathe- 
matics, and medicine. While in the Western world all 
philosophical speculation followed closely in the path 
of St. Augustine with Plato as a starting-point, the 
Arabians preferred the leadership of Aristotle: ''Parmi 
les philosophes grecs on choisit de preference Aristote, 
sans doute parce que sa methode empirique s'accordait 
mieux que I'idealisme de Platon avec la tendance scien- 
tifique et positive des Arabes. ' '^-"^ 

Together with this scientific disposition, there was 
in the Arabian mind a tendency towards mysticism ; the 
Orient has ever been the home of mysticism. ^^® When, 
therefore, the Syrians presented the scientific lore of 
Aristotle, tinctured with Neo-Platonic mysticism,^" the 
Arabians accepted it with little hesitation. These are the 
principal sources that determine the Arabian theory of 
sensation. 

Avicenna, the princeps philosophorum among the 
Arabians, maintains that all perception, all knowledge, 
implies the reception of the form of the object perceived 



12* Pollak, Arch. f. Gesch. d. Philos., 1904, p. 211. 

125 Ibid. 

126 Stockl., Op. cit., IF, p. 1-lflf. 

127 Pollak, Ibid. 

38 



THE SPECIES SENSIBILIS 39 

by the subject perceiving/^^ As Forget states this prin- 
ciple of Avicenna: ''La perception d'un objet a lieu 
lorsque son entite se trouve presente dans le sujet per- 
cevant et est contemplee par ce qui, en lui, pent percevoir. 
De deux choses I'une: ou bien cette entite est la realite 
meme de la chose qui existe en dehors du sujet percevant 
pendant qu ' il percoit ; . . . ou bien cette entite est une 
image de la realite de I'objet, retracee dans la personne 
du sujet percevant et non separee de lui; c'est I'hy- 
pothese restante. "^-^ He demands, therefore, the union 
of subject and object as a condition for all perception. He 
concedes, too, that the object may be present in the sub- 
ject according to a mode of being, other than its mode of 
being in the order of nature : it may be present in a rep- 
resentative image. The distinctive feature of sensation 
as a form of knowledge is that the sense receives the form 
of the object as it exists in concreto, that is, not ab- 
stracted from matter or from the conditions of matter. ^^"^ 

Augustinian psychology considered spirit so far 
superior to matter, that soul and body could not be sub- 
stantially one. The Arabians differed from this view. 
They accepted Aristotle's doctrine that soul and body are 
one substance, of which the soul is the form and the body 
is the matter. The soul is the "perfectio prima corporis 
naturalis instrumentalis habentis opera vitae. ' '^^^ Being 
the active principle in man, the soul determines his es- 
sence and makes him to be what he is : ''Le rapport de la 
matiere a la forme est le rapport du cuivre a la stat- 
ue. ' "^^ But the Arabians tear down what they have built 
up on these principles by introducing a tertimn quid, 
an intermediary between body and soul. 

Since, according to St. Augustine, the difference be- 
tween matter and spirit is so great that mutual inter- 



m Winter, Avicennas Opus egregium de Anima, p. 38. 

129 Rev. Neo-scol., 1888, p. 24. 

130 Winter, Op. cit., p. 39. 

131 Winter, Op. cit., p. 20; cf.. Forget, Op. cit., p. 25. 
'■'2 Carra de Vaux, Avicenne, p. 212. 



40 THE SCHOLASTIC THEORY OF 

action is impossible, it was quite logical for him to 
postulate an internal medium, an air-like substance 
through which the soul could act upon the body. But 
not only St. Augustine and other Platonists demand this 
intermediary; even Aristotle explains the interaction of 
body and soul by the vital warmth.'^^ With the Arabians 
the idea of a medium is generally accepted, and it re- 
ceived a relatively fixed form in their doctrine of the 
spiritus. 

Costa-ben-Luca, a Syrian physician and philosopher, 
gives us the most complete and most systematic account 
of the doctrine of the spiritus, prevalent among the Ara- 
bians, in his "De Differentia Spiritus et Animae."^'* 
We read there : ' ' Omnis spiritus, qui f uerit in his parti- 
bus subtilior et melior, et clarior et fortior erit ad recipi- 
endum actus animae ceteris partibus corporis, et aptior 
secundum quantitatem subtilitatis et claritatis recipiet 
de actibus animae. ' '"^ This spiritus is ' ' quoddam corpus 
subtile quod in humano corpore oritur ex corde et fertur 
in assurienet, i.e., in venis pulsus ad vivificandum corpus. 
. . . Similiter oritur ex cerebro et nervis et operatur 
sensum et motum.""*' The former, the spiritus vitalis, 
operates the vital functions in the body, such as growth, 
circulation, and respiration; the latter, the spiritus ani- 
malis, arises from the spiritus vitalis, for he says: **De 
pulsibus ipsis contextis extenditur quaedam pars sub 
cerebro petens inferiora cerebri, apta ad recipiendum 
spiritum auimalem, trahens ei spiritum vel partem de 
spiritu vitali, quem diximus esse in ventriculis cordis."^" 
Located in the brain and in the nerves, the spiritus ani- 
malis operates sensation and motion. Besides, it is the 
proximate cause of thought; **in quibusdam enim est 
subtilis et clarus, et hie est rationabilis, cogitans dispo- 



"3 Siebeck, Gesch. d. Psychol., P. p. 137. 
'3'' Barach, Bibliothcca philos. med. aetatis. 
"» Op. cit., c. IV. 
"* Op. cit., c. I. 
1" Op. cit., c. II. 



THE SPECIES SENSIBILIS 41 

sitione et bonae cogitationis ; est autem in quibusdam 
corruptus eritque talis amens, irrationabilis, levis atque 
stiiltus."^^^ The spiritus in the anterior ventricle of the 
brain operates sensation ; the one in the middle ventricle, 
thought and knowledge; and the one in the posterior 
ventricle, memory and motion. ^^^ 

Sensation is an actio a parte ohjecti, and a passio 
a parte subjecti; this is another concept which is funda- 
mental in the Arabian theory of sensation. St. Augus- 
tine pictured sensation as an action going out from the 
subject to the object. In the Arabian theory this is re- 
versed; the object is active, the subject is acted upon; 
''ex proprietate lucis est operari in visum, ex natura 
visus est, pati ex luce.""° The sense does not suffer the 
loss of anything, but it suffers in so far that, being af- 
fected from without, it receives something. In other 
words, a quality of the object causes a change in the 
sense; the sense becomes like to the object.^*^ Hence the 
Brothers of Purity say: "Sinnliche Wahrnehmung ist 
nichts mehr als dass die Mischung des Sinnes dem sinnlich 
Wahrgenommenen in der Qualitat gleich werde, und die 
Seele von der Anderung dieser Mischungen wisse.""" 

This change in the subject, however, is not affected 
by the emanation of el'SwXa from the object. Avicenna ex- 
plicitly rejects this theory of Democritus and of the 
''secta naturalium. ""^ Being a qualitative change, not 
a quantitative one,^** it is rather of the nature of pain: 
''Ista operatio, quam operatur lux in glacialem, est ex 
genere doloris."^*^ Ordinarily this affection is so slight 
that we are not conscious thereof. It must, however, 
reach a certain intensity before perception is aroused; 



138 Ibid. 

139 Op. cit., c. IV. 

"0 Bauer, Die Psychol. Alhazens, p. 23. 

"1 Ibid. 

142 Dieterici, Philos. d. Araber, Bk. VII, p. 30. 

i« Winter, op. cit., p. 39. 

i« Ibid. 

"^ Bauer, op. cit., p. 47. 



42 THE SCHOLASTIC THEORY OF 

on the other hand, if it be too severe, the sense-organ is 
injured,"" This reference to the threshold of sensation 
is probably the earliest recorded in history. 

How then do the Arabians conceive of the origin of 
sensation? Avicenna expresses this very briefly: 
''Forma visi pervenit ad visum translucente reddente 
ipsam.""^ He rejects the theories of light-rays proceed- 
ing from the eye to the object, or of light-rays from the 
eye mixing with the light of the atmosphere."^ After 
discussing the nature of light, of the transparent, of 
color, of reflex light, and other problems of experimental 
psychology (which merits for him the distinction of leader 
in this science), he concludes that, after all, sensation is a 
psychical process which takes place when the form of the 
object comes in contact with the sense."'' 

Alhazen treats at length of the origin of vision in his 
''De Aspectibus."^^" Light, he tells us, is the objective 
element in vision, and the sense of sight is the passive 
element. Every object of sight, and every part thereof, 
sends out in all directions direct or reflected light- 
waves.^^^ These strike the eye. Alhazen then gives us 
an anatomy of the eye, pointing out the function and 
teleology of the various parts, all of which is, indeed, not 
original, but it is the first attempt at a systematic treat- 
ment of this subject. ^^^ It is in these discussions about 
the medium and about the sense-organ, that the scientific 
bent of the Arabian mind shows itself. 

Since then, according to the author of "De Aspecti- 
bus," the surface of the eye is a convex lens, those light- 
waves only which strike it perpendicularly pass unbroken 
through the transparent body, the humor glacialis; all 
others are deflected. In a way, the light-waves form a 



"« Ibid. 

147 Winter, op. cit., p. 48. 

i« Ibid. 

1^9 Winter, op. cit., p. 45(T. 

"0 Cf. Baeumkcr, Witelo, p. 232. 

161 Cf. Siebeck, Arch. f. Ge.sch. d. Philos., II, p. 41.5tf. 

1^- Bauer, op. cit., p. 11. 



THE SPECIES SENSIBILIS 43 

pyramid, having the object as base and the eye as apex.^''^ 
Nor is the mere color of the object carried to the eye by 
the light-waves; the form also, or rather the ''intentions 
of form," such as size, figure and distance, are carried 
aiong.^^* In a word, a picture of the object, diminished in 
size, but proportionate, is thrown on the lens of the eye 
as on a mirror/^'^ Alhazen, too, expressly rejects the 
e'l'ScoXov- theory of Democritus."*' 

The lens, however, as Alhazen admits, does not per- 
ceive. It merely receives the light and is atf ected thereby. 
The spiritus in the optic nerve converts this atfection or 
pain into a perceptive quality, a knowledge-object; 
"(spiritus) dat virtutem sensibilem. ""^ The spiritus is 
the medium between the light-ray in the lens and the 
perception which is completed in the "ultimum sen- 
tiens."^^^ Here, then, is the whole process of vision in 
the words of Avicenna: "Visus perficitur humore crys- 
talloide, qui est sicut aqua limpida quae recipit formas 
visibilium et reddit eas spiritui visibili et fit perfectio 
videndi in contractu nervorum concavorum, sicut cogni- 
tum est ex ejus chirurgia et ostensione dispositionis 
suae."^^' 

But what is the position of the Arabians regarding the 
species sensibilis f Aristotle is said to have inspired their 
theory of sensation, hence we should expect some trace of 
his eI5os-theory. Avicenna, treating of vision, says the 
TVTTOL of objects spread out in the transparent when this 
latter becomes actually transparent by the presence of 
light ; they fall upon the eye as upon a mirror. This view 
he ascribes to Aristotle."° As we have seen above, both 
Avicenna and Alhazen speak of the form of the object 



"3 Op. cit., 18ff. 

i« Op. cit., p. 28. 

165 Op. cit., p. 18. 

i5« Op. cit., p. 28. 

1" Op. cit., p. 18. 

"8 Op. cit., p. 29. 

169 Winter, op. cit., p. 26. 

^^ Landauer, Ztschr. d. d. Morgenl. Gess., Bd. 29. 



44 THE SCHOLASTIC THEORY OF 

which is received by the sentient subject. Beyond this 
they are not very explicit. As Carra de Vanx says of 
Avicenna: "Notre philosophe admet qui'l y a, dans la 
vision, un fantome de 1 'object, qui se trouve renvoye par 
la lumiere vers I'oeil; mais il ne precise pas davantage 
cette theorie que nous ne I'avons fait cidessus."^" 

But what is this form, this tvttos, of which they 
speak? According to Avicenna, the "formae sensibiles" 
are accidents of the object that affect the sense. For 
instance, the forms of sight are color, size, appearance, 
expression, etc."^ These are impressed upon the sense 
together with the physical impression of light on the eye. 
Alhazen says the form which passes through the humor 
glacialis is a diminutive of the object. Both reject the 
theory of Democritus, of material particles emanating 
from the object. Nevertheless, they maintain that the 
form of the object is received by the humor crystalloidos 
as an image is received by water ;^*'^ the virtus sensitiva 
perceives light "ex illuminatione " spiritus, and color "ex 
coloratione" spiritus."* But the humor crystalloidos, 
being material, can, indeed, receive a material impression, 
but not a representative "esse" from an object; the 
spiritus, which in its ultimate analysis is but air-like mat- 
ter, cannot be colored except by material color. More- 
over, the reception of this form is not only a passio in 
the broad metaphysical meaning of passio. Being of the 
nature of pain, it may even injure the sense-organ. Hence 
this reception can refer only to the reception of the physi- 
cal impression by the organ. In reality, then, the 76x05 
of the Arabians is the material impression of physical 
qualities or accidents on the sense-organ. Avicenna ex- 
pressly states as much when he enumerates the "formao 
sensibiles" of sight."'' If over and above this they de- 

'" Op. cit., p. 212. 

'82 Winter, op. cit., p. 28. 
'« Winter, op. cit., p. 2G. 
'*^ Bauer, op. cit., p. 29. 
1*^ Winter, op. cit., p. 28. 



THE SPECIES SENSIBILIS 45 

mand that the true form of the object, or a representative 
esse of the object, be present to the subject in sensation, 
it comes, not from the object, but from some other source. 
And this, too, they admit. Avicenna maintains this form 
is produced in the mind, as it is in matter itself, from the 
world of intelligences.^"" The affection or change pro- 
duced in the sense-organ by a quality of the object is but 
the occasion upon which the true form of the object arises 
in the mind from the world of intelligences.^" 

In fact, we perceive the object of sensation only indi- 
rectly; the direct or immediate object of the sense-faculty 
is the affection of our sense-organs. ' ' Sentiens est aliquo 
modo sentiens seipsum, non corpus sensatum;""^ or as 
Alhazen has it: "Color comprehenditur a sentiente ex 
alteratione formae corporis sentientis et ex ejus colora- 
tione."^"'* As we saw above, the spiritus sensibilis be- 
comes colored, and the sense becoming aware of this, it 
indirectly becomes aware of the object which causes the 
change in the spiritus. Finally, the Brothers of Purity 
emphasize the same, when they say that sensation is noth- 
ing more than a change in the sense-organ, of which the 
soul becomes aware. ^^° 

The above is far from a complete account of the 
Arabian theory of sensation. It will, however, suffice to 
trace the development of the species sensibilis among 
Scholastics, and more is not intended. We have based 
this account on Avicenna, because of all Arabians, he 
exerted the greatest influence on European thought. Al- 
hazen was drawn upon, because his ' ' De Aspectibus ' ' was 
the last word on optics among the Arabians.^^^ It was 
popularized in the West by Witelo's "Perspectiva.""' 



1** Baeumker, op. cit., p. 472. 

"^ Siebeck, Gesch. d. Psychol., P, p. 436. 

16S Winter, op. cit., p. 40. 

^^ Bauer, op. cit., p. 47. 

"» Dieterici, op. cit., Bk. VII, p. 30. 

»" Arch. f. Gesch. d. Philos., II, p. 415ff. 

"* Baeumker, op. cit., p. 609. 



46 THE SCHOLASTIC THEORY OF 

There, too, its authority was unquestioned, as Eoger 
Bacon testifies: "Plenitudo autem sapientiae istorum 
duorum philosophorum (Alhazen and Ptolemy) in libris 
manifestat, quod nullum falsum dicunt, et ideo ipsi in 
libris Aspectuum sunt de illis auctoribus, qui in omnibus 
sunt recipiendi . . . quod florem philosophiae explorant 
sine falsitate qualibet.'"" Though not a treatise on psy- 
chology, we can readily deduce Alhazen 's theory of sensa- 
tion from the "De Aspectibus."^^* The "De Differentia 
Spiritus et Animae" was introduced, because the theory 
of an internal medium is closely connected with the Scho- 
lactic theory of sensation in the eleventh and twelfth cen- 
turies. Finally, the Brothers of Purity, who were eclectic 
philosophers, show us the effect of the theoretical specu- 
lations of Arabian philosophers on the less educated 
Arabian public. We may, then, regard the above account 
as fairly representative of the Arabian theory of 
sensation. 

From what has been recorded it appears that the 
Arabians misinterpreted Aristotle. He had contended 
that the tvtos in the sense was not material, but was a 
representative image of the object itself. The Arabians 
claimed Aristotle as their guide and authority; still the 
TVTTos, according to them, as we have seen, could only be 
material. In order to maintain, in spite of this view of 
the TVTTOS, Aristotle's concept of knowledge, namely, the 
presence of the form of the object in the subject, they 
have recourse to Neo-Platonic emanationism ; i.e., the 
form of the object comes to the subject from the world of 
intelligences. Again, to preserve the terminology of Aris- 
totle, they introduce a two-fold use of "form": as that 
which makes a thing to be what it is, and again, as a 
quality or an accident of the object. This merely adds 
to the confusion. 



"3 De Multiplicatione Specienini, III, 3 (ed. Bridges, p. 513). 
"* Bauer, op. cit., p. 39. 



I 



THE SPECIES SENSIBILIS 47 

The representative view of sensation is another seri- 
ous departure from Aristotle. The latter regarded the 
TVT0S as an instrument or means in which we perceive the 
object immediately. The Arabians, however, regard the 
TVTTos , i.e., the change in the sense-organ, as the direct 
object of the sense-faculty, from which we conclude to 
the cause of this change, the external object. 

We should, indeed, hesitate to speak of the Arabian 
theory as a species-theory — it differs so widely from the 
eI5os -theory of Aristotle — were this not necessary to 
trace the modification and development of the species- 
theory in the Scholastics of the eleventh and twelfth 
centuries. 

THE SCHOOL OF CHARTRES.~The School of 
Cliartres in the twelfth century inaugurated a new line ot 
tliought in Western medieval philosophy.^" By training 
and by inclination the representatives of this school 
were Platonists. John of Salisbury, who studied at Char- 
tres, calls Bernard of Chartres ''perfectissimus inter 
Platonicos saeculi nostri."^^** William of Conches re- 
peatedly professes his adherence to ''Plato, omnium phi- 
losophorum doctissimus. "^'^^ William, in fact, wrote a 
commentary on Plato's Timaeus, which latter served as 
the basis for the metaphysics of the school. 

This loyalty to Plato was due in a large measure to 
the humanistic reverence of the School of Chartres for 
all that was ancient and classical. ''Dicebat Bernardus 
Carnotensis, nos esse quasi nanos, gigantium humeris in- 
sidentes, ut possimus plura eis et remontiora videre, non 
utique proprii visus acumine, aut eminentia corporis, sed 
quia in altum subvehimur et extollimur magnitudine gi- 
gantea. ' '^^^ Plato had been followed by the early Church 



"6 Poole, Illustrations of Medieval Tliought, p. 113. 
"« Metal., IV, 35. 
"' Cf. Dragmaticon. 
"8 Metalog., Ill, 4. 



48 THE SCHOLASTIC THEORY OF 

Fathers; besides, the School of Chartres knew no other 
ancient classics in philosophy, since Aristotle was looked 
upon as a logician only."'' 

And yet the spirit of the School of Chartres was not 
Platonic. Nature study was one of its features. Para- 
phrasing the words of St. Paul, William of Conches says : 
' ' By the knowledge of the creature we attain to the knowl- 
edge of the Creator. ' "^"^ Besides, the ideology of William 
is quite different from that of Plato. Instead of rejecting 
knowledge obtained through the senses as useless and 
deceitful, William regards sense-knowledge as the foun- 
dation of all science and thought."^ His psychology is 
not purely Platonic in spite of his praises of Plato. In 
the "Dragmaticon" we read: "Discernere ergo et intel- 
ligere animae est; sentire vero et similia^ corj^oris."^®^ 
But as a thorough-going Platonist he should have as- 
cribed all activity to the soul and none to the body. The 
divergence between the School of Chartres and Plato was 
so marked that John of Salisbury says : ' ' Egerunt opero- 
sius Bernardus Carnotensis et ejus sectatores, ut com- 
ponerent inter Aristotelem et Platonem, sed eos tarde 
venisse arbitror, et laborasse in vanum ut reconciliarent 
mortuos, qui, quamdiu in vita licuit, dissenserunt. ""^ 

But the feature which makes the School of Chartres 
one of particular interest for our investigation is their 
attention to the study of physiology and anatomy.^^* It 
is in this connection that they develop the earliest traces 
of the materialistic aspect of the species sensibilis in the 
history of Scholasticism. 

William of Conches, among the foremost of this school, 
treats of sensation in the fourth book of the ''Dragmati- 
con.""^ De Wulf says of him: "Through the versions 



"9 Ibid. IV, 3; cf . Annales de Philos. chret., XVI, p. 160. 
'80 Phil., IV, 41. 

181 Poole, op. cit., p. 130. 

182 IV, 5. 

183 Metalog., II, 17. 

184 Cf . Clerval, Les Ecoles de Chartres, pp. 240, 320, ff. 
18B P. L. 90, c. 1127flE. 



THE SPECIES SENSIBILIS 49 

of Constantine the African, William became familiar with 
the physiological theories of Galen and Hippocrates, and 
endeavored to harmonize them with the process of sense- 
knowledge. It was Constantine who introduced into the 
schools of the West the study of the physiological con- 
comitant of sensation; and the excessive attention paid 
to this aspect of knowledge resulted in almost completely 
losing sight of its distinctly psychical aspect. "^^*' To 
verify these words we need but open the "Dragmati- 
con.'"*'^ The brain, according to William, is made up of 
three parts *4n prora, in medio, et in puppi." The first 
part, called the "phantastica" or ''visualis," is the seat 
of vision and intelligence; ''haec calida et sicca est, ut 
formas rerum et colores attrahat." The middle part, the 
"logistica," is the seat of reason and judgment; '^estque 
calida et humida ut melius discernendo proprietatibus 
rerum se conformet." The third and last part is the 
^'memorialis"; '4sta est frigida et sicca ut melius retin- 
eat; frigidi et sicci est constringere." These facts, he 
claims, have been proved by the experience of persons 
who have been injured in these several parts. This whole 
description William has from Constantine the African.^®^ 

So, too, he gives us a process of sight taken almost 
verbatim from Constantine. After describing the anatomy 
and function of the eye, he continues : ' ' Cum igitur ani- 
malis spiritus per nervos a cerebro prodeuntes, et ad 
oculos usque pervenerit, exiens si aliquem exteriorem 
splendorem, vel solis, vel alterius, receperit, usque ad 
obstaculum dirigitur, quod offendens per ipsum se diffun- 
dit, formisque illius et coloribus informatur per oculos, et 
per phantasticam cellam ad logisticam cellam transit, 
visusque effi'citur. ' '^®^ 

Hearing he explains in a similar manner : ' ' Cum aer 
naturalibus instrumentis percussus formam vocis accep- 



'86 Op. cit., 185. 
i«7 Bk. IV, V. 

^"8 Cf. Soury, Systeme nerveux central. 
i«9 Op. cit. 



50 THE SCHOLASTIC THEORY OF 

erit, exiens, primam partem aeris quam reperit, simili 
informat forma, et ilia aliam, donee ad aures perveniatur 
ad modum sicci et concavi; ciii resonant! excitatur ille 
spiritus animalis, descendensque ad aures per quosdam 
nervos, informat se simili forma, sicque informatiis ad 
logisticam cellam revertens, auditum operatur."^^*^ The 
process of the other senses he does not record, but says 
they proceed in a manner similar to vision and hearing. 

At first sight we are unable to determine which influ- 
ence is predominant in this theory of sensation, that of 
St. Augustine or that of the Arabians ; evidently both are 
present. According to St. Augustine, as we have seen, 
the sense goes out to the object of sensation. William of 
Conches rejects the theories of the Stoics and the Atom- 
ists, and adds : "Nobis vero ilia placet sententia, quod ani- 
malis spiritus usque ad rem pervenit. "^^^ Substituting 
''sense" for ''animalis spiritus," this is the same as 
St. Augustine's view. Both emphasize the activity of 
the subject, and the corresponding passive character of 
the object. Again, in William's theory as in that of St. 
Augustine, the sense or spiritus is informed, and this 
"informatio" comes from the object; "formisque illius et 
coloribus informatur per oculos." Of hearing, William 
says :" Spiritus animalis . . . informat se simili forma. " 
Recalling now the distinction, which was made when 
speaking of St. Augustine, between the subject as the 
active cause, the object as the material cause, and the 
organ as the instrument of the "informatio," it is equally 
justifiable to say the spiritus is informed by the object 
(passively at least) through the organ, or to say the 
spiritus informs itself with a form like to that of the 
object. 

The similarity, then, between the Augustinian theory 
of sensation and that of William of Conches is striking. 



1"° Ibid. 
"1 Ibid 



i 

I 



THE SPECIES SENSIBILIS 51 

But on the other hand we observe a decided divergence 
between the two. William emphasizes the physiological 
process that accompanies sensation; St. Augustine 
scarcely mentions this. The localization of psychical 
faculties in the brain, the anatomy of the sense-organs, 
the definite role ascribed to the nerves and to the spiritus 
— these are the elements in William's theory of sensation 
which are not due to St. Augustine, but rather to the 
Arabians. 

Moreover, for St. Augustine the form which informs 
the sense, is truly an image of the object ; not so in Wil- 
liam 's theory. He speaks of forms and colors as comple- 
menting each other; he even uses "forma" and "figura" 
promiscuously in the Dragmaticon. Besides, if the 
"phantastica" of the brain is warm and dry "ut formas 
rerum et colores attrahat," and if the "logistica" is 
warm and moist "ut . . . proprietatibus rerum se confor- 
met," this is evidence that the "forms" of which he 
speaks are, in the first place, accidents or qualities of 
things and not their essence ; secondly, they are material, 
because attracted by a material brain, or, because a 
material brain conforms itself to them. 

Finally, however subtle and fine the spiritus may be, 
it is material. If, then, this is informed, or informs itself, 
this can be only by material forms. The Arabian view 
of the species or tvtos is evident here. As that view can 
hardly be called a species-theory, even so Turner says of 
William of Conches: "Rejecting the theory of forms 
mediating between object and subject, he devotes his 
attention to what we should call the physiological aspect 
of the problems of psychology. ' "^^ 

The relation of William of Conches to the Scholastics 
of the thirteenth century regarding the theory of sensa- 
tion is analogous with that of Democritus to Aristotle ; ho 
observed the facts, but lacked the metaphysics to explain 
them. 



192 Op. cit., p. 



52 THE SCHOLASTIC THEORY OF 

William of Conches is not alone in this materialistic 
aspect of the species sensibilis. To quote another repre- 
sentative of the School of Chartres, Bernard Sylvester 
says in his "De Mundi Universitate":^^^ ''Molle et deli- 
quatum ad creationem cerebri visa est delegisse, ut in 
liquido possent facilius rerum imagines insidere. ... In 
sincipite provisum est, phantasia rerum formas anticipet 
et rationi renunciet quae viderit universa. In occipitis 
reductiore thalamo memoria conquiescat ne, si primo vis- 
ionum jacuisset in limine, figurarum frequentissimis per- 
turbetur incursibus.""* So much is clear from these 
words: the images which are impressed on the brain 
must be material; ''form" is used synonomously with 
^'figure"; in short, then, we have an image-theory which 
is less foreign to the eiScoXov-theory of Democritus than 
to the eZSos-theory of Aristotle. 

John of Salisbury, too, ''is apparently influenced by 
the physiological method of William of Conches. ' ""' He 
is, in the main, Platonic. Still he says : ' ' ars sive scientia 
originem trahit a sensu. ' ""^ But he is more important as 
a chronicler than as an original thinker. 

William of Thierry emphasizes the same line of 
thought. The spiritus, the development of which he 
traces very minutely in his "De Natura Corporis et 
Animae,'"^^ is "quaedam vis animae, per quam virtutes 
suos actus operantur." Nevertheless, it is corporeal. 
The spiritus visivus proceeds from the brain through the 
optic nerve to the tunica vitrea of the eye, and, by stimu- 
lating this tunica, makes the lens radiant. Passing then 
to the surface, the spiritus mixes with the lighted air, re- 
ceives the colors of objects, and conveys the impression 
or change to the crystal lens. 



"3 Barach, op. cit. 

»»^ Op. cit., p. 64. 

1'^ Turner, op. cit., p. 300. 

'« Metalog., IV, 20. 

i»' P. L., 180. c. 95ff. 



THE SPECIES SENSIBILIS 53 

As soon as the mind perceives this change of the crys- 
tal lens through the activity of the spiritus visivus, it per- 
ceives the color, form, size and motion of external objects. 
**Aer exterior visibilium colorum fert mutationes et 
spiritus eamdem menti infert mutationem. Omnis enim 
sensus sentientem transmutat quodammodo in id quo sen- 
titur." In hearing the 'Cactus aeris p,ervenit ad operi- 
mentum nervorum . . . ibique ipsum operimentum in 
naturam tacti aeris transmutatur. Sunt enim similia, 
quia natura utraque aeria. Haec autem permutatio ad 
mentem ducitur per nervos, mens autem discernit natu- 
ram intromissae vocis, et sic fit auditus.""^ 

This theory of William of Thierry seems less fantastic 
than some others of this age. The spiritus, considered as 
a power of the soul, would be less objectionable, but he at 
once calls it corporeal and thereby returns to the old 
Arabian doctrine. Besides, Arabian subjectivism is no- 
ticeable. The mind perceives directly the states of bodily 
affection and only indirectly, the external object. In this 
regard the theory bears some resemblance to that of the 
early Peripatetics and to that of Galen. Adelard of Bath 
must also be mentioned in this connection, because in his 
''Quaestiones Naturales" he gives expression to similar 
views regarding sensation.^''^ Like all the philosophers 
of his time (ca. 1100), he is a Platonist. Chalcidius, 
Boethius, and St. Augaistine are his authorities. Hence 
his theory of sensation, indeed, his whole psychol- 
ogy, is a compilation from their works. The ori- 
gin of sight he explains as did Plato; concerning the 
origin of hearing he follows Boethius.^!*^ Still we find 
introduced ' ' a theory on the localization of mental func- 
tions and a number of physiological informations coming 
directly from Galen and Hippocrates . . . borrowed by 
Adelard from Constantine the African."^" In his "D^ 



198 Ibid. 

199 Baumgartner, Die Philos. d. Alanus de Insulis, p. 18. 

200 Willner, Adelards De eodem et diverse, p. 43. 
^oi De Wulf, op. cit., p. 187. 



54 THE SCHOLASTIC THEORY OF 

Eodem et Diverse ' ' Adelard speaks rather disparagingly 
of sensation as a faculty of knowledge. ^°- 

THE SCHOOL OF ST. VICTOR.— The most import- 
ant school of the twelfth century, next to that of Chartres, 
was the School of St. Victor. The Augustinian doctrines 
concerning the inferiority of matter and the correspond- 
ing importance of spirit have ever been fundamental in 
schools of mysticism. This, too, is true of the School 
of St. Victor. Hugh of St. Victor considered body and 
soul to be more closely united than was warranted by the 
traditional psychology, but he failed to find a suitable 
formula to express this union.^°^ Instead of adopting a 
new formula, he attempted to improve upon the old one 
of Plato. He maintained that the union between body 
and soul is a strained and unnatural one, and that, there- 
fore, the soul is impeded in its activity by its union to 
the body. However, he plainly seemed dissatisfied with 
this explanation.^"* Richard of St. Victor is the first to 
call the union of body and soul a natural union : "Econtra 
vero proprium est humanae naturae pluralitatem substan- 
tiarum habere in unitate personae. Nam quod humana 
persona in simplicitate substantiae quandoque invenitur, 
non de naturae ipsius conditione sed de conditionis ipsius 
corruptione fore deprehenditur. ' '-°^ 

According to Hugh of St. Victor, the number of the 
senses is determined by the difference of the sense-organs. 
Hence he concludes that after death all sensation will 
be one and the same, and while he expresses the opinion 
that sensation might be possible even now without the 
organs of sense, he at the same time concedes his un- 
certainty about this.""" 



202 Willner, op. cit., p. 45. 

203 Ostler, Die Psychologic d. Hugo v. St. Victor, p. 6i. 
2<« Ibid. 

205 De Trinit.. IV. 25 (Ostler, op. cit., p. 89). 
208 Sacra in., 2, XVI. 3. 



THE SPECIES SENSIBILIS 55 

Such views about sensation, added to the Platonic 
character of Hugh's psychology^"^ and the tone of mysti- 
cism in all his works, led Haureau^"* to doubt the authen- 
ticity of the interesting little work, '*De Unione Corporis 
et Spiritus;" for, in this work we find a rather complete 
account of the species-theory. But today it is generally 
acknowledged to be an authentic work of Hugh of St. 
Victor. 

The passage which refers to the species is the follow- 
ing: "Ipsa vis ignea, quae extrinsecus formata sensus 
dicitur, eadem forma usque ad intimum traducta imagina- 
tio vocatur. Forma namque rei sensibilis per radios 
visionis foras concepta, operante natura, ad oculos usque 
retrahitur, atque ab eisdem suscepta visio nominatur. 
Deinde per septem oculorum tunicos et tres humores 
transiens, novissime purificata et collata introrsum ad 
cerebrum usque traducitur, et imaginatio efficitur. Pos- 
tea eadem imaginatio ab anteriore parte capitis ad me- 
diam transiens, ipsam animae rationalis substantiam con- 
tingit, et excitat discretionem in tantum jam purificata et 
subtilis effecta, ut ipsi spiritui immediate conjungatur; 
veraciter tamen naturam corporis retinens et proprieta- 
tem, ut constat quod scriptum est; Quod natum est ex 
carne, caro est (Joan. III.). . . . Ergo imaginatio nihil 
aliud est quam similitudo corporis, per sensus quidem 
corporeos ex corporum contactu concepta extrinsecus, at- 
que per eosdem sensus introsum ad partem puriorem 
corporei spiritus reducta, eique impressa."^"^ 

From this it appears that Hugh considers the sense a 
''vis ignea" which is informed by an external object. 
That an image of the object be in the subject is a condi- 
tion for all knowledge."" Hence sensation is essentially 
a passive process by which the form of the object is im- 



^^ Cf. Mignon, Hugues de St. Victor, p. 102. 
2°* Hugues de S. Victor, Nouvel Examen. 
'<» P. L., vol. 177. c. 387. 
"« Didascal., I. 2. 



56 THE SCHOLASTIC THEORY OF 

pressed, first on the medium, and then on the sense-organ. 
Sight is an exception to this general rule, because the 
light-rays go out from the eye. 

Certainly the whole passage reads much like St. Au- 
gustine, and his influence is undeniable. The physiologi- 
cal factor of sensation is not uppermost, as we have seen 
it in William of Conches and in others of the twelfth cen- 
tury. Moreover, the distinction between the process of 
sight and that of the other senses was observed even 
in St. Augustine, though Hugh expresses this more 
emphaticall3^ 

But there are other features in this theory of Hugh, 
which are not based on St. Augustine. In the first place, 
the form in the sense is material as is evident from 
Hugh's own words: ''Veraciter tamen naturam corporis 
retinens et proprietatem. " The purification which this 
form undergoes by passing through material parts of the 
eye, and the effect which it produces on a corporeal spirit, 
are equally foreign to Augustinian thought. These, as 
well as the passive character of sensation, the function of 
the spiritus, and the physiology and teleology of the 
sense-organs are evident traces of Arabian influence. Sie- 
beck says of Hugh of St. Victor : "In der Art, wie er sich 
ihr (der Sinne) Verhaltniss zur Wahrnehmung denkt, 
stimmt Hugo mit der allgemeinen Anschauungsweise 
iiberein, welche das Mittelalter fiber diesen Punkt besass. 
Er denkt sich die Empfindungsinhalte als von aussen in 
das Organ hereingekommene Bilder der Dinge (inten- 
tionale Species) und zwar bestimmter als eine Art Ab- 
drucke derselben im Pneuma (der spiritalis natura)."-^^ 
We take no objection to the last sentence. But the former 
indicates the loose concept which Siebeck has of the spe 
cies sensibilis. We have already observed a decided dif- 
ference between the Augustinian concept of these 
*' Bilder" and that of Hugh, and we shall observe an 



"2 Gesch. d. Psychol. 



THE SPECIES SENSIBILIS 57 

equally marked divergence from Hugh's concept in the 
later Scholastics. No wonder that Siebeck finds traces 
of Democritus in the Scholastic theory of the species 
sensibilis ! 

In the twelfth century another work, ' ' Liber de Spiritu 
et Anima," was often ascribed to Hugh of St. Victor; 
others ascribed it to St. Augiistine.^^^ The work is a 
compilation drawn mostly from the writings of those two 
renowned authors. Now it is commonly ascribed to Al- 
cher of Clairvaux. The psychology of the ''De Spiritu 
et Anima" is purely Augustinian. But, as Eitter ob- 
serves, ^^* it is remarkable how much attention is given to 
the union of body and soul. This union is described as a 
friendly one, though the body impedes the activity of the 
soul. The soul is in a prison, but "it is devoted to its 
prison. "^^^ Then, too, the localization of the psychical 
functions and the role of the spiritus are discussed at 
length. 

Concerning the species sensibilis, the " Liber de Spiritu 
et Anima" offers nothing new; it restates the views of 
St. Augustine and of Hugh of St. Victor. The senses 
receive the corporeal forms of bodily objects. These are 
impressed on the spiritus which is not a body but similar 
to a body.^" The soul gathers these ' ' visibiles actualium 
f ormas per sensuum passiones. ' '^^^ Again we read : ' ' Sen- 
sus est passio animae in corpore ex qualitatibus extra 
accidentibus."^^* All this points to the influence of Ara- 
bian thought. Though it is not new, it deserves a men- 
tion, because, under the reputed authorship of St. Augus- 
tine or of Hugh of St. Victor, this work of Alcher was re- 
garded very highly and was commonly used in the twelfth 
century as a textbook of psychology. Hence the views 



213 Cf. De Wulf, op. cit., p. 202. 
2" Gesch. d. Philos., VII, p. 591. 
21B De Wulf, op. cit., p. 202. 

"6 C. X. 
2" c. XI. 

218 C. XXXVIII. 



58 THE SCHOLASTIC THEORY OF 

here expressed were firmly rooted in the philosophy of the 
age. That Alcher accepted the faulty Arabian concept 
of form when speaking of sensation, is confirmed by 
the fact that even Alanus de Insulis, at the end of the 
twelfth century, speaks of accidental and essential forms, 
i.e., properties. ^^® 

The materialistic aspect of the species sensibilis, as we 
have traced it, was the result of engrafting Arabian phys- 
ics and physiology upon Platonic or Augustinian psychol- 
ogy. It was characteristic of all the middle ages to re- 
vere authority and tradition, and to accept a ready-made 
solution of any problem in preference to formulating a 
new solution. Now, the psychology of Plato had become 
sacred both because of its ancient classical fame, and 
because it had been followed by all the early Christian 
schools. Moreover, to the Scholastics of the twelfth 
century no other classical psycholog}^ was known. As 
we observed when treating of the School of Chartres, 
Aristotle was, indeed, regarded highly as a logician and 
as a natural scientist, but not as yet, as a psychologist or 
metaphysician. Hence these early scholastics accepted 
the psychology of Plato in spite of their own convictions. 
"We have seen that some of the above-mentioned philoso- 
phers were not satisfied with all the principles of Platonic 
psychology, but they dared not offer a substitute. 

On the other hand, as Barach--° observes in his intro- 
duction to the *'De Motu Cordis" by Alfred of Sareshel, 
we notice in the twelfth century a tendency to find a ma- 
terial basis for psychical and vital phenomena. Contact 
with Arabian learning gave the first impetus to this new 
field of thought. But here, too, the twelfth century philos- 
ophers were not original ; they accepted the Arabian sci- 
ence in gloho. 

Together with that, they accepted the Arabian view 



"' Baumgartner, Alanus de Insulis, p. 53. 
^ Op. cit. 



THE SPECIES SENSIBILIS 59 

of sensation. No longer content with the psychical aspect 
of sensation which neglected or disregarded altogether 
the objective element, they went to the opposite extreme 
by emphasizing unduly its physical and physiological con- 
comitants. In consequence of this, they lost sight of the 
psychical nature of sensation. The old terminology was, 
indeed, retained but it was interpreted in a materialistic 
sense. The form, image, or species in the sense, meant 
little more than the physical impression on the material 
organ of sense. 

As a further consequence of this materialistic aspect 
of the species, these philosophers, as we have seen, fav- 
ored the representative view of sensation which was prev- 
alent among the Arabians. Sensation meant simply the 
awareness of the affection from without, or of the change 
in the sense-organ. The species, if such it may be called, 
became the direct object of sense-knowledge, instead of a 
means to this knowledge ; the external object was known 
only mediately, as a deduction from the impression on the 
organ. The species was considered the principium quod, 
instead of the principium quo cognitionis. 

This materialistic aspect of the species sensibilis re- 
mained uppermost until the works of Aristotle in the 
original Greek were made known to the Scholastics, i.e., 
until the early decades of the thirteenth century. There- 
upon this view gave way, not suddenly, but gradually, to 
the psycho-physical aspect of the species sensibilis. 



CHAPTER III. 
THE PSYCHO-PHYSICAL ASPECT 

OF THE 

SPECIES SENSIBILIS. 

The Latin translations of all the works of Aristotle 
together with Arabian commentaries suggested to the 
Scholastics of the thirteenth century new solutions to 
problems of psychology. This not only added to their 
fund of knowledge, but likewise increased the difiiculty of 
unifying or systematizing it. Instead of the two hetero- 
genous elements which we have noticed in the psychology 
of the twelfth century, we now find four more or less 
distinct psychological systems ; for, together with Aristo- 
telianism, Neo-Platonic emanationism was added to the 
traditional Augustinian and the materialistic Arabian 
tendencies. In the early decades of the thirteenth cen- 
tury these were still unassimilated. To harmonize them 
and weld them into one complete system was the aim of 
every philosopher, with the result that sometimes one, 
sometimes another view predominated. One by one, how- 
ever, the contradictory elements were eliminated. Thus, 
even the most loyal Platonists of the thirteenth century 
admitted the active influence of the object in sensation, 
whereas earlier Platonists had contended that the object 
was merely the occasion which aroused the activity of the 
sense. It is likely that this change was brought about by 
the Arabians who compromised by accepting Plato's view 
regarding the origin of "sapientia," and Aristotle's 
view regarding the origin of ' ' scientia. ' '"^ Other compro- 
mises were effected in a similar manner. 

The distinctive feature of the psycho-physical aspect 
of the species sensibilis is the influence of Aristotle. At 
first this is far from preponderant, though it is distinctly 



221 Cf. Manser, Jahrb. f. Philos, u. spek. Thcol.. Rd. ^26, p. 31G. 
60 



THE SPECIES SENSIBILIS 61 

noticeable. Just as many doctrines of Plato and Aristo- 
tle had been foreshadowed in Pre-Socratic philosophy, 
even so the philosophers of the twelfth century had 
hinted at many doctrines developed and crystalized in the 
thirteenth century.^^^ However, just as Humanism opened 
new fields of thought in the fifteenth century, so, too, the 
introduction of Aristotle brought a new point of view to 
the philosophy of the thirteenth century. There was not 
a break in the development, not a difference of standard 
or purpose in philosophy, but new means and new ma- 
terial suggested new solutions of old problems. 

ALFRED OF SARE8HEL.— The first evidence of 
this psychophysical view is offered by the ''De Motu Cor- 
dis ' ' of Alfred of Sareshel.^^^ Written between 1205-1215, 
this is among the earliest works of Scholastic philosophy 
which show traces of the Greek-Latin translations of 
Aristotle's works including the ^'De Anima."-^* Never- 
theless, the predominant note is not Aristotelian psychol- 
ogy, but rather Arabian physiology and anatomy. 

Alfred boldly rejects all traditional, that is, all Augus- 
tinian psychology. Occasionally he ''borders on the ma- 
terialism of the ancient Grecian physicians."-'" The 
"warmth," of which he makes mention so frequently, is 
material, since it atfects the blood, causing nutrition, 
growth, etc.^^® 

Again Neo-Platonic emanationism, as expressed in 
Avicebron's "Fons Vitae" and in the "Liber de Causis," 
is apparent throughout the work.'" Thus he says the soul 
is not created; "anima e quieto sempiterno nata.""* He 
likewise presents a twofold concept of the soul: "In 
se enim considerata, substantia est incorporea, intellec- 



222 Cf. Rev. Thomiste, '97, p. 723. 

223 Barach, op. cit. 

224 Philos. Jahrb., 14, p. 478. 

225 De Wulf, op. cit., p. 276. 

226 Barach, op. cit., p. 91. 

227 Op. cit., p. 25. 

228 Op. cit., p. 103. 



62 THE SCHOLASTIC THEORY OF 

tiva, ilhiminationum quae a primo sunt, ultima relatione 
perceptiva. . . . Kelata vero anima perfectio est corporis 
organici. "^-^ Still, being imbued with ''Arabian tenden- 
cies in physiology and psychology, "^^° he attempts to lo- 
calize this "substantia incorporea," not in the brain, but 
in the heart. -^^ His proof is insufficient ; but we are inter- 
ested in the fact that such a doctrine could have been sin- 
cerely believed, more than in the proof for this belief. 

Alfred has little to say regarding the origin and pro- 
gress of sensation considered objectively. But we find 
many allusions to the subjective element, the mechanism, 
of the senses, though he does not treat of this either ex 
prof esse. The soul as the ''perfectio prima corporis" is, 
of course, the principal cause of sensation. And, since 
the heart is the seat of the soul, "ipsum (cor) igitur et 
sensus et motus et vitae primum erit instrumentum. ' '^^- 

However, sensation is not an act of the soul alone. 
' ' Neque anima vel corpus dormit vel digerit, ratiocinatur 
vel sentit, sed animal. Non ergo animae vel corporis 
propria hujusmodi passio vel actus aliquis, sed ani- 
malis."-^^ This passage might be taken to indicate that 
Alfred had grasped Aristotle's theory of sensation, or one 
of its features, viz., the cooperation of body and soul. But 
his view is based, not on the peripatetic doctrine of the 
substantial union of body and soul, but on a pantheistic 
emanationistic concept of the soul. The soul is to the 
body what God is to the world, "das Formprincip. "-'* 
Emanation or irradiation is his watchword. 

In the doctrine of the spiritiis Alfred is very similar 
to Costa ben Luca. He distinguishes between the spir- 
itus animalis and the spiritus vitalis.'^^ The purpose of 
the spiritus is to receive impressions immediately from 



229 Op. cit., p. 83. 

230 De Wiilf, op. cit., p. 276. 

231 Barach, op. cit., p. 9.5, 
"2 Op. cit.. p. 99. 

23' Op. cit., p. 109. 
23^ Op. cit., p. 93ff. 
236 Op. cit., p. 95. 



THE SPECIES SENSIBILIS 63 

the soul, and to affect immediately the body. Henee it is 
nearly material and nearly spiritual. ''Anima enim ex 
sanguine spiritum medio calore producit, productum vero 
sine medio ad operationem disponit. "^^"^ ''Materia hujus 
(spiritus) : subtilissima et parvissima pars sanguinis ab 
epate ad cor ascendentis. ... Ex aere ignito videtur 
constare."^" This is the spiritus vitalis. The spiritus 
animalis which operates motion and sensation is even 
more subtle and pure.^^® It arises out of the spiritus vita- 
lis which, coming to the brain by irradiation, is there puri- 
fied and becomes spiritus animalis.-^^ The brain is like a 
polished mirror; the spiritus vitalis strikes this mirror, 
and the reflection which is purer, i.e., less material, than 
the object reflected, is the spiritus animalis. "Ex (ejus) 
raritate et concavitate ' ' the brain is the principal seat of 
the spiritus.^*" From there it passes to the other or- 
gans through the nerves. The brain, therefore, controls 
sensation, motion, etc. "Sensus et motus phantasiae, 
aestimationis, rationis, memoriae regimen tenet. ' '^*^ Still 
the causa principalis of sensation is the soul since" a corde 
quoque ad cerebrum ad eundem effectum (irradiationem 
spiritus) venae directae sunt; his enim inter sectis non 
sentit animal. "^^- The causa propria of sensation is the 
spiritus ; the brain is the ' ' spirituum . . . domicilium. ' '^*^ 
When the head is diseased the senses are languid, when 
the heart is diseased the senses cease.^** 

Finally, "nervi vero instrumenta sunt sentiendi et 
motus. "'*^ Alfred distinguishes three kinds of nerves: 
sensory nerves, and these are "subtilissimi"; motory 
nerves, these are "grossiores"; and a third kind which 



236 Op. cit., p. 107. 

237 Op. cit., p. 96. 

238 Op. cit., p. 98. 

239 Op. cit., p. 99. 
2^0 Ibid. 

2« Op. cit., p. 87. 

2« Op. cit.. p. 112; cf. p. 93 and p. 95. 

2« Op. cit., p. 108. 



' Op. cit., p. 99. 
' Op. cit., p. 107. 



64 THE SCHOLASTIC THEORY OF 

performs both functions, "et hi medii in quantitate 
sunt."'**^ 

This leads us to Alfred's definition of sensation: ''Est 
enim sensus perceptio impressionis aequalitatem super- 
gredientis. "-*^ In a fragment of another work likewise 
published by Baraeh, Alfred says: "Oportet enim ut 
instrumentum exteriorum applicatione aliquo modo affici- 
atur; quam affectionem pereipiens anima sentit."^*® Al- 
fred, then, considers affection from without as essential 
for sensation. But this is not an affection of the soul ; it 
is an affection of the "instrumentum," the sense-organ. 
The soul is purely active, since it merely perceives thi? 
impression. 

Alfred's view of sensation resembles that of Plotinus 
who rejected the impression of forms ;^*^ hence the ab- 
sence of a species-theory in Alfred. That the body is 
affected in sensation could easily be explained by the 
physics and physiology of the Arabians, with which Alfred 
was conversant ; that the soul becomes aware of this, he 
could ascribe to the vague and mysterious function of 
the spiritus. Moreover, the soul is "illuminationum quae 
a primo sunt, ultima relatione perceptiva."^^" From this 
we may assume that Alfred accepted also the other view 
of Plotinus regarding sensation, namely, that the form 
enters the mind from the world of intelligences. Alfred, 
then, had no need for anything like a species sensibilis. 

That the works of Aristotle exerted an influence on 
Alfred may be conceded; some would even find a simi- 
larity of style between the two."" But it is apparent that 
the influence of Arabian science and of Neo-Platonism, as 
presented by Arabian commentators, is uppermost. How- 
ever, the"De Motu Cordis "is anything but an unified sys- 



2« Op. cit., p. 108. 

2" Op. cit., p. 103. 

2« Op. cit., p. 114. 

2"* Siebc<;k, Geach. d. Psychol. . P. p. 323. 

25« Baraeh, op. cit., p. 83. 

251 Op. cit.. p. 31. 



THE SPECIES SENSIBILIS 65 

tematic whole, Haureau calls it ^'ecrit vraiment curieux 
ou les plus decevantes, les plus frivoles conjectures sont 
naivement recommandees au nom d'une science impar- 
faite."'^' 

Another unfortunate feature of the *'De Motu Cor- 
dis" is the utter disregard for all traditional views. 
Owing to this defect more than to any other, its influence 
on the philosophical thought of the thirteenth century 
was minimal. "^^ As Barach observes: ''Man kann von 
Nachwirkungen der Schrift De Motu Cordis im eigent- 
lichen Sinne des Wortes nicht sprechen. Die in ihr ent- 
wickelte anthropologische Gesammtansicht scheint 
spurlos voriibergegangen zu sein."^'* 

WILLIAM OF AUVERGNE.— One of the most im- 
portant indirect effects of Arabian philosophy on the 
Christian schools of Europe was the revival of interest 
in psychology, particularly in the problem of know- 
ledge.^^^ The Arabian Neo-Platonic doctrines of emana- 
tionism, of phantastic intelligences; and other such 
theories of knowledge had to be combated. If the world 
of spiritual intelligences is not the source of knowledge, 
what, then, is its origin? 

This was the problem of philosophy that confronted 
William of Auvergne. William knew all the works of 
Aristotle, though only from translations. He was, like- 
wise, conversant with most of the important works of 
Arabian and Jewish philosophers f^^ he speaks of Avice- 
bron as "unicus omnium philosophantium nobilissi- 
mus."^" But the Christian adaptation of Aristotle was 
still in its first stage. The genuine Aristotle was not yet 



-*2 Hist, de la philos. scolast.. P p. 65. 
"^^De Wulf, op. cit., p. 276. 
2W Op. cit., p. 65. 

285 Baumgartner, Die Erkenutnisslehre d. Win. v. Auvergne, p. 10; cf. 
Ueberweg, II. p. 279. 

258 Baumgartner, op. cit., p. 5. 
2" De Wulf, op. cit., p. 273. 



66 THE SCHOLASTIC THEORY OF 

distinguished from Arabian accretions. Tlie Stagirite 
was respected, indeed, as the founder of peripatetic phil- 
osophy, as a man of great knowledge especially in the 
natural sciences, but not so much as a metaphysician or 
psychologist.^^® As a consequence, William combated the 
Arabian doctrines concerning the origin of knowledge 
by means of the traditional Augustinian psychology. Not 
that he gives us a unified systematic treatise on the 
theory of knowledge, but, dispersed throughout his works 
especially his ^'De Anima," we find many questions re- 
lating to this problem presented and discussed. 

In all essentials the psychology of William of Au- 
vergne is Augustinian.^^^ The influence of Aristotle is 
noticeable in new problems discussed and in a new ter- 
minology, rather than in a new line of argumentation. 
He defines the soul as "perfectio corporis physici organic! 
vitam habentis," but he adds: ''Non intret autem in ani- 
mum tuum, quod ego velim uti sermonibus Aristotelis 
tamquam authenticis ad probationem eorum quae dic- 
turus sum."-*^" On the contrary, he places himself with 
the psychologists of former centuries, when he defines the 
soul as ' * substantiam viventem, incorpoream, intelligen- 
tem, et scientem per se et proprie, totumque homi- 
nem, hoc est omnia interiora hominis et exteriora, 
regentem. ' '-^^ 

The nature and qualities of the soul are, according to 
William, directly opposed to those of the body. Hence 
body and soul are complete independent substances.'-'^* 
While he speaks of the relation between body and soul 
as that of matter and form, he destroys the significance 
of these terms when he calls the body the house of, the 
instrument of, the vessel containing, the soul.''^"'' The 



2^^ Baumgartner, op. cit., p. 10. 

269 'Werner, D. Psychol, d. Wm. v. Auvergne, Sitzungsber. d. wiener 
Akad., vol. 73, p. 263. 

2^" Baumgartner, op. cit., pp. 11 and 12; (De An., I, 1, p. 65.). 

2" Ibid; (De An., I, 3, p. 67). 

2«2 Op. cit., p. 13; (De An., I, 2, p. 66). 

263 Ibid. (De An., II, 9, p. 125). 



THE SPECIES SENSIBILIS 67 

union is effected ''per eontactum virtntis." "Animam 
rationalem sive liumanam esse substantiam activam et 
agentem in semetipsam et in corpus. "^^* 

The soul is absolutely indivisible ; there is no division 
of faculties. Hence all activity, intellectual, sensible, 
and vegetative, has for its subject the immaterial soul. 
"Ipsae enim operationes, quae fiunt per corpus, ut osten- 
sum est tibi in praecedentibus, ipsius animae humanae 
verissime ac propriissime sunt, sicut est loqui, disputare 
et etiam, quamquam indignetur Aristoteles, texere et 
aedificare. "-''" These activities of the soul depend on 
the body, not for their existence, but for their activity; 
the organs of the body are necessary conditions, means, 
or instruments of the soul, "Ista indigentia (corporis) 
est solummodo quantum ad operationes hujusmodi jjera- 
gendas, quemadmodum cytharedus indiget cythara quan- 
tum ad operationem cytharizandi exercendum, non autem 
quantum ad esse vel existere suum."-*"' Essentially sen- 
sation, for instance, is an emanation from the soul, just 
as the soul is an emanation from the Fons Vitae, from 
God.-'^' However, "potentia hujusmodi non exit in actum 
per se ipsam solum, imo necessarium habet instrumen- 
tum videndi. ' '^*''* 

All knowledge implies the assimilation of the object 
by the subject in some manner, and this, too, is true of 
sensation. "Omnis cognitio nostra assimilatio quaedam 
est ad ipsa cognita secundum eam vim vel partem, per 
quam cognoscuntur ; ut si per sensus cognoscuntur, as- 
similatio erit sensus ad ilia, ut evidens est in tact^ et 
visu et in omnibus sensibus."-*^^ This assimilation takes 
place in the organ of sense; the sense is affected and 
changed by the impression from the object. "Si sit visio 
albi, erit assimilatio albi et oculi et albatio oculi, sic 



2" Op. cit., p. 14; (De An. V, 8, p. 124). 

266 Op. cit., p. 24; (De An., Ill, 11, p. 102). 

266 Cf. Haureau, op. cit., II, p. 155 (De An., XXIII, 5). 

26^ Baumgartner, op. cit., p. 18. 

26* Op. cit., p. 24; (De An., V. 23, p. 149). 

263 Op. cit., p. 28; (De Un., II, p. 1, c. 14, p. 821). 



68 THE SCHOLASTIC THEORY OF 

visio lucidi illuminatio oculi. ' '-' "^ The change in the organ 
of sense is produced by the impression of images or 
forms. ''Sensus enim ... est potentia habens for- 
mas sensibiles sive similitudines earum."^^^ There is no 
sensation possible without this action of the external 
object on the sense organ; ''corpus enim agens in corpus 
per formas sensibiles." ''In organo enim uniuscujusque 
sensus necesse est imprimi similitudinem ejus, quod per 
ipsum sensibiliter cognoscitur seu sentitur."-^^ This 
change of the organ is in the nature of a passio, a state 
of being acted upon from without. Not that the soul is 
acted upon; this he denies, because the soul, being imma- 
terial, cannot be affected by matter.^''^ But the material 
organ of sense is acted upon b}^ the object. This passio, 
however, William interprets to mean merely the recep- 
tion of physical qualities of the object, just as potentia 
for him means merely the aptitude of receiving physical 
qualities of objects. "Si virtus intellectiva non esset in 
corpore humano nisi quemadmodum receptibilitas for- 
marum visibilium aut quemadmodum in speculo politio 
et tersio."^^* 

But how do these images of forms come in contact 
with the sense-organs? William offers no solution; he 
seems to imply that there is no difficulty. The doctrme 
of a medium between object and sense is useless : "Inter 
sensus et sensibilia non est necessaria virtus media agens 
in sensus, quae faciat sensata sensibilia, quae potentia 
sunt in organis sensuum, exire in effectum et ea esse in 
effectu; sed ad hoc sufficiunt sensibilia quae extra 
sunt."^" 

All this, the impression, the assimilation, the medium, 
if there be one, is only the pln^sical element of sensation, 



"0 Op. cit., p. 29; (De retrib. sanct, Tom. I, p. 317). 

2" Op. cit., p. 28; (De An., Ill, 4, p. 207). 

"'2 Op. cit., p. 29; (De An., V. 5, p. 119). 

"3 Ibid. 

2'< Ibid. (De An., V, 5, p. 120). 

"6 Haureau, op. cit., IF, p. 152; (De An., IV, 7). 



THE SPECIES SENSIBILIS 69 

only a necessary requisite. The real act of sensation is 
purely psychical, because it implies perception, judgment, 
and knowledge. ''Verum nemo adhuc eo usque deliravit, 
ut diceret nervum vel spiritum visibilem aliquid cognos- 
cere vel de aliquo judicare. ' '""^ It is necessary that sensi- 
ble forms be received, but ' ' receptibilitas f ormarum visi- 
bilium non facit oculum potentem videre sive aptum vel 
idoneum ad videndum.""^ We require moreover '^cog- 
nitionem sive judicium quod per illam (formam sensi- 
bilem) fit tamquam per signum."^^^ **Quod enim colores 
apprehendit vel pereipit et de eis judicateosqueabinvicem 
dijudicat et discernit, hoc proprie ac vere ac solum 
videns est."-^'' The soul therefore sees and hears; the 
soul is the subject of sensation. The impression of forms, 
on the sense organs, the change in the organs — these are 
but the occasion that arouses the soul to activity. "Levis- 
sime commotus (a rebus) earum species ipse sibi ipsi 
semetipso format. "^^^ 

In the last analysis, therefore, William of Auvergne 's 
theory of sensation is purely Augustinian.^^^ The soul 
knows or sees itself in sensation as in every process of 
knowledge ; the bodily organs are but instruments arous- 
ing the soul to self-activity ; matter is opposed to spirit ; 
body and soul are independent substances — what is this 
but Platonic dualism! From his terminology we might 
infer that William followed Aristotle ; indeed, he accepts 
a number of Aristotle's v.iews, or fragments thereof. ^^' 
But he fails to grasp Aristotle's line of reasoning, fails 
to see the complete synthesis and interdependence of all 
the parts. Thus, he knows no animated organ; his con- 
cepts of passio and potentia are material; form or 
imago, too, is for him merely a physical quality of 



2'6 Baumgartner, op. cit., p. 30; (De An., I, 5, p. 70). 
2" Op. cit., p. 31; (De An., V, 5, p. 120). 
278 Op. cit., p. 32; (De An., V, 5, p. 69). 
"9 Ibid. (De An., V, 6, p. 121). 

280 Cf. Turner, op. cit., p. 326. 

281 Baumgartner, op. cit., p. 33fl. 

282 Baumgartner, op. cit., p. 6. 



70 THE SCHOLASTIC THEORY OF 

an object; and the role of the medium in Aristotelian 
psychology he misinterprets and consequently rejects.^*' 
This materialistic interpretation of Aristotle's meta- 
physical concepts is easily explainable, almost pardon- 
able. William knew no Greek; translations from the 
Arabian were his principal sources and these were ma- 
terialistic. In fact, even the Greek peripatetics them- 
selves whom the Arabians studied, had fallen from the 
metaphysical heights of their great teacher. 

Neo-Platonic elements, also, are evident in William's 
theory of sensation; as, for instance, the views border- 
ing on emanationism.^"* Sensation emanates from the 
the soul ; the soul is on the horizon between the material 
and the immaterial world. These tendencies are, likely 
enough, drawn from the Fons Vitae, and from the 
Liher de causis, which was, after Aristotle, the most 
influential authority for medieval philosophers. 

Arabian philosophy is responsible for another ele- 
ment in the theory of sensation as presented by William 
of Auvergne, viz., the physiological element.-^" Though 
this feature is not as prominent in his works as it is in 
those of the Arabians, or even of some Christian philos- 
ophers of the twelfth century, e. g., William of Conches, 
still, he makes mention of the localization of the faculties 
in the brain, of the soul in the heart, of the formation of 
the eye, of the upper and lower limit of sensation, and 
of the stimulus of sensation. 

To conclude, William of Auvergne is a "typical rep- 
resentative of the period of transition and elaboration 
to which he belongs."'^® He knew Arabian Aristotelian 
philosophy, but its merit was not yet definitely deter- 
mined. He was a kind of "go-between" from the old 
Augustinian to the new peripatetic psychology.-*' Instead 



283 Baumgartner, op. cit., p. 30ff. 

2** Baumgartner, op. cit., p. 18. 

28^ Baumgartner, op. cit., p. 26; cf. Vallois, Guillaume d' Auvergne. 

286 De Wulf, op. cit., p. 273. 

287 Siebeck, Gesch. d. Psychol., P, p. 426. 



THE SPECIES SENSIBILIS 71 

of rejecting the old and boldly accepting the new, he tried 
to compromise and harmonize them, which was im- 
possible. As a consequence, we notice a lack of sureness, 
of definiteness, ''a characteristic lack of doctrinal co- 
hesion. "^®^ This lack of system, lack of clearness in 
thought and style, accounts for the negligible influence of 
William of Auvergne on subsequent philosophy. 

THE FRANCISCAN SCHOOL.— The Franciscan 
School of the thirteenth century shows a remarkable ad- 
vance towards the unification and systematization of 
Scholastic philosophy. When, in 1209, St. Francis 
founded the Order of Friars Minor he had little thought 
of raising the intellectual standard of the age. But, 
as Felder remarks,^^^ any religious community with an 
aim and a constitution like that of the Franciscans, will 
naturally develop the pursuit of science and culture. As 
a matter of fact, however, it happened '^dass die wis- 
senschaftliche Arbeit von Aussen hereingetragen, nicht 
im (Franziskaner) Orden erwachsen ist."^^° For, about 
1231, Alexander of Hales, at that time the most illustrious 
professor at Paris, took the Franciscan habit, and it was 
he who gave the first impetus and pointed out the general 
direction to early Franciscan philosophy and theology.^^^ 

At that time the ecclesiastical prohibition or restric- 
tion concerning the works of Aristotle was practically 
disregarded, though not officially removed.-^^ As a result, 
the new peripateticism based on Aristotle was becoming 
more and more prominent. Alexander was conservative. 
In theology St. Augustine, St. John Damascene, and 
Peter Lombard were his guides; in philosophy he in- 
clined toward the new peripateticism, though his train- 
ing had been along the lines of Augustinian thought. 



288 De Wulf, op. cit.,_p. 274. 

2*^ Studien im Franziskanerorden, p. 12. 

2»» Endres, Alexander v. Hales, p. 31. 

2«' Felder, op. cit., p. 177. 

=52 Felder. op. cit., p. 179. 



72 THE SCHOLASTIC THEORY OF 

Hence, whenever possible, lie attempts a compromise be- 
tween the traditional Augustinian view and the new Aris- 
totelianism. Of course, he does not treat of philosophy 
systematically, but merely as a help to theologj' ; this may 
to some extent explain his inconsistency, favoring at 
one time the opinion of St. Augustine and at another 
time that of Aristotle, whichever is more advantageous 
for the desired conclusion. Whether we should say with 
Siebeck^^^ that Alexander applied Avicenna's philosophy 
to all questions of theology, and when this did not satisfy, 
referred to St. Augustine, St. John Damascene, Boethius, 
and others; or whether we should not rather invert the 
order of precedence, — this may be an open question. So 
much, however, is clear: Alexander attempted a fusion 
of these two lines of thought ; an attempt which, in psy- 
chology, at least, was necessarily disastrous. ^^* 

This general characterization applies with equal truth 
to the illustrious pupils of Alexander : John de la Rochelle 
and St. Bonaventure. Both these start where Alexander 
leaves off, the one in philosophy, the other in theology. 
That St. Bonaventure should develop the theology of his 
master seems in harmony with the spirit of the thirteenth 
century; but that John de la Rochelle, a professor of 
theology, should devote his ''Summa de Anima" wholly 
to philosoph}^ is rather surprising. 

ALEXANDER OF HALES.— Alexandev of Hales 
speaks of the union of soul and body as an "unio nativa 
. . . ad modum formae cum materia. "-°^ Soul and body 
become one ''per compositionem quia unum illorum est 
possibile respectu alterius, non tantum ut mobile respectu 
motoris, sed ut materialis respectu suae perf ectionis. ' '-''" 
The soul is the "actus naturalis corporis completi in 



293 Arch. f. Gesch. d. Philos., Bd. II, p. 180. 

29^ De Wulf, op. (it., p. 280. 

295 Sum. theol., II, q. 63, m. 1, res. 

296 II, q. 63, m. 7, ad 1. 



THE SPECIES SENSIBILIS 73 

forma natural!. "^^^ It is united to tlie body *'ut motor 
mobili et ut perfectio formalis suo perf ectibili. "^^^ The 
body, on the other hand, has the ''potentia"^^^ to be in- 
formed by the soul, and, indeed, needs the soul, ' ' indiget 
anima.'""" When, therefore, Alexander compares the 
union of soul and body to that of a sailor in his ship,'*'^ 
he does not call in question the substantial union of the 
two, but he emphasizes another doctrine which he, and 
most Franciscans after him, borrow from Avicebron, 
namely, that the soul is not only the form of the body, 
but also an "ens in se praeter hoc quod est actus cor- 
poris; ... est substantia praeter substantiam cor- 
poris."^"- Again, when Alexander speaks of media 
between soul and body, he postulates these, not for the 
union of soul and body as "perfectio perf ectibili, " but 
to mediate the interaction of the two.^°^ 

If the psychological doctrines expressed in the Summa 
of Alexander are on the whole elementary and incom- 
plete, this is particularly true concerning the jjroblem 
of sensation. "°* Imbued with the views of St. Augustine, 
he underrates the importance of sensation, considering 
it an inferior means of knowledge,^°^ and, therefore, re- 
stricts his discussion of sensation to three questions : Is 
sensation one faculty! Are there five senses! How 
is their number determined? Even these are, in 
part, treated too briefly to be intelligible. Nor are his 
arguments always conclusive.^"*^ We can, however, deduce 
from his meager allusions that he considers soul and 
body as co-principles of sensation, and that, to his mind, 
the subject of sensation is atfected by the object and is 



2" II, q. 63, ra. 4, ad 6n. 

2'* II, q. 63, m. 1, res. 

^^^ II, q. 62, m. 6. 

^w" II, q. 63, m. 1, res. 

501 II, q. 69, m. 2. 

302 II, q. 59, m. 2; cf. Endres, op. cit., p. 203. 

303 Endres, op. cit., p. 220. 

304 Endres, op. cit., p. 224; cf. Philos. Jabr., '15, p. 143. 
30* II, q. 69, m. 2. 

308 Cf. St. Thorn., S. Theol., I, q. 78, a. 3. 



74 THE SCHOLASTIC THEORY OF 

partly passive. ^°'' He plainly expresses the necessity of 
an external medium'^**' and of a "species in organo in- 
teriore et exteriore. ' "°° Whether he conceived of this 
species as a material accident, following herein the 
Arabians, or whether he accepted St. Augustine's view 
of the species, is best determined in the light of the 
explicit teaching of his pupil, John de la Rochelle. 

JOHN DE LA ROCHELLE.— The starting-point of 
John's "Summa de Anima" is the psychology of Alex- 
ander. He does not slavishly follow his master; for 
instance, de la Rochelle denies that the soul is composed 
of matter and form,'^° which was affirmed by Alexander. 
But his theory of sensation differs from that of his 
teacher only in so far as John's is more complete, more 
explicit, and more didactic. 

John de la Rochelle is the first of the medieval philoso- 
phers to say that body and soul are one substance: "Ex 
amina et corpore fit unum secundum substantiam, quod 
est homo."^^^ It is the union of "forma suae materiae," 
of "perfectio suo perf ectibili. "^" From this aspect, the 
union is immediate, ' ' sine medio. ' ' Considering the body 
as an instrument or an organ of the soul, the psychical 
faculties or powers may be called media between soul 
and body.^^^ Further intermediaries conditioning the inter- 
action of soul and body, which are by nature most dis- 
similar, are the sensitive and vegetative nature, the 
spiritus, and the "natura elementaris. "^^* The spiritus 
he defines as "vehiculum virium animae, et est corpus 
subtile, spirituale, diffusum in concavitatibus membrorurn 
a natura quintae essentiae."^^^ 



3»^ II, q. 66, m. 3. 

'»' Ibid. 

3«» II, q. 67, m. 4.. 

^^° Summa de Amina, Domeniclielli's ed., p. 118. 

311 Op. cit., p. 170. 

"12 Op. cit., p. 163. 

313 Ibid. 

3" Op. cit., p. 166. 

315 Op. cit., p. 167. 



THE SPECIES SENSIBILIS 75 

The sense, according to John, is that power of the 
soul "quae rerum corporearum percipit formas prae- 
sentes.""® The soul has the power to receive "species 
spirituales intelligibiliter, ' ' and ' * similitudines corporales 
sensibiliter. "^^^ It is "receptiva omnium similitudinum 
et speeierum.""^ The soul, then, is passive, since it re- 
ceives, or is affected from without ; ' ' unde species animae 
dicuntur passiones.'"^'' In this, too, consists the faculty 
of knowing, because all knowledge takes place "per re- 
ceptionem similitudinis. ' "^^ 

But the soul is not by itself the principle of sensa- 
tion. "(Sensus) vires tarn animae quam corporis dici 
possunt, quia ab anima in corpore fiunt, nee sine utroque 
fieri possunt."^^^ All sensation "fiat per corpus. "'^^^ It is, 
therefore, not correct to say: "Virtus visiva videt, vel 
pupilla videt ; " we must say : ' ' Oculus videt qui ex virtute 
visiva et pupilla constituitur. ' '^^^ The nerves, too, and the 
spiritus are required as means for sensation.^^* 

Besides these internal media of sensation, an ex- 
ternal medium is necessary. If the object and the sense- 
organ were in immediate contact, we could in some cases 
have no sensation at all, e. g., in sight; and in no case 
could we have simultaneous perception of opposite quali- 
ties. "Necessarium ergo fuit medium in quolibet 
sensu.'"-^ The function of this external medium is to 
convey an image or a "species" of the object to the 
sense-organ. This is effected, says John, by the action 
of the medium : ' ' Sensus enim visus recipit per actionem 
lucis speciem coloris ; ' "'*' "per operationes lucis 



316 Op. cit., p. 227. 
3" Op. cit., p. 112. 

318 Op. cit., p. 132. 

319 Op. cit., p. 191. 

320 Op. cit., p. 152. 

321 Op. cit., p. 224. 

322 p. 253. 

323 Op. cit., p. 172. 

324 Op. cit., p. 256. 

325 Op. cit., p. 257. 
328 Op. cit., p. 293. 



76 THE SCHOLASTIC THEORY OF 

species coloris abstrahnntur quodammodo et pupillae 
copulantur. ' '^" 

The existence of the species is emphasized over and 
over in the "Summa de Anima." ''Sensus enim fit per 
receptionem speciei vel similitudinis objecti non per re- 
ceptionem ipsius secundum essentiam."^-^ This species 
abstracted b}^ the action of the medium, is impressed 
upon the medium and thus conveyed to the sense. 
*' Medium immutatum immutat auditum."^^^ Color, odor, 
and the like are qualities ''quae inferunt passiones sen- 
sui."^^° Precisely by these "sensuum passiones" the 
sense receives the forms of sensible things.''^^ This de- 
scription of the origin of sensation is plainly peripatetic ; 
and still de la Rochelle presents St. Augustine's theory 
of vision without comment or criticism.^^^ 

But what is this species of which John de la Rochelle 
speaks so freely? This is precisely the point of our 
investigation. Haureau says John's doctrine of the spe- 
cies is "feconde en consequences. ... Or une de ces 
consequences, la plus prochaine, est que toute percep- 
tion est une reception, et que les sens ne recevant pas les 
objets euxmemes, en recoivent les especes, les images. 
Cette declaration est done la premier mot d'un faux sys- 
teme, si ce n'est pas le dernier. "^^^ 

We have seen that the Scholastics of the twelfth cen- 
tury accepted the Arabian interpretation of Aristotle *s 
TVTTos. We have again observed that the Scholastics of 
the early decades of the thirteen century were not noted 
for their originality. This might lead us to expect the 
same materialistic aspect of the species from de la 
Rochelle. And, indeed, we find many expressions in the 
"De Anima" of John, which seem to substantiate this 



^ Op. cit., p. 293. 

328 Op. cit., p. 293. 

323 Op. cit., p. 257. 

»3o Op. cit., p. 255, 

"1 Op. cit., p. 234. 

«!" Op. cit., p. 224; cf. p. 253. 

«« Op. cit.. P, p. 205. 



THE SPECIES SENSIBILIS 77 

view. For instance, we read : " In exteriore tamen sensu 
sunt accidentia rermn sensibilium;"^-^* "oculus recipit 
formam materialem et situalem ; "^^^ the " aestimativa " 
is a ^*vis transcendens . . . quia appreliensio sua non 
est formarum sensibilium et materialium, sed immateri- 
alium.'"^*' Moreover, the species changes the material 
medium : ' ' Sonus . . . immutat aerem medium . . . 
imprimendo ei suam speciem ; ' "" ' ' caro calef acta medium 
sit in tactu ad sentiendum calorem."^^^ All these ex- 
pressions suggest a species in accordance with the 
Arabian concept of the species, that is, a material picture 
or miniature of the object in the sense-organ. 

But contrary to the above expressions, we are in- 
formed: "Sensus exterior comprehendit speciem prae- 
sentem in materia et simplicem. "^^^ The species, then, 
exists, indeed, "in materia," but it is simple and, there- 
fore, not material. Just as the *' materia prima" has the 
aptitude of receiving all natural forms, so the soul has 
the aptitude of receiving all intelligible and sensible 
forms. ^*° Hence the forms which enter the soul in sensa- 
tion are not material; "aliter species et imagines sensi- 
biles in ea facerent distantiam. "^" When, then, we read 
of material forms in the sense, we must interpret these 
expressions in the light of the following: ''Licet sensus 
sit susceptivus specierum sensibilium praeter materiam, 
tamen ut in materia. ' '^^' 

According to the Arabians, the species is a quality of 
the object affecting the sense-organ. But de la Rochelle 
tells us the species arises in the sense through this affec- 
tion of the organ: "Visibiles actualium formas, per 



' Op. cit., p. 267. 
5 Op. cit., p. 117. 
' Op. cit., p. 267. 
' Op. cit., p. 255. 
* Ibid. 

» Op. cit., p. 231. 
' Op. cit., p. 218. 
I Op. cit., p. 166. 
■ Op. cit., p. 155. 



78 THE SCHOLASTIC THEORY OF 

sensuum passiones (mens) colligit.'"*^ He admits with 
Avicenna that the external sense does not receive the 
form ''quae est in materia, sed ejus similitudinem vel 
ei simile.'"" Surely the image is not more material than 
the object which it represents. 

Again, his argument for an external medium is based 
on the contention that then we could not perceive oppo- 
site sense-qualities ''nisi alteratus (sensus ).""*' But a 
material species would in no way relieve the difficulty; 
we still should be unable to perceive opposite qualities 
without a change in the sense-organ. 

Finally, John de la Rochelle, like all Scholastics, de- 
mands that in knowledge subject and object be in some 
way united. But he admits no emanation of forms nor 
innate ideas, at least not for our knowledge of the sen- 
sible world.^**^ The object itself must, therefore, be some- 
how united to the sense. The object cannot be united to 
the sense secundum essentiam. Hence he must con- 
ceive of it as united per speciem vel similitudinem. 
According to John de la Rochelle, then, the species is the 
object itself in another mode of being, produced, indeed, 
by a material object, but not itself material, since it 
affects and exists in an immaterial sense. Once de la 
Rochelle uses the word "tipos," but not with any specific 
meaning; he applies it to "formas eorum quae (anima) 
opinata est et quae intellexerat. "^*' 

The influence of Arabian philosophy appears in the 
attention given to the physical and physiological processes 
that accompany sensation. As Turner ^^^ and De Wulf^** 
state, John exaggerates the importance of these factors ; 
still, they are far less prominent in the "Summa de Ani- 
ma" of de la Rochelle than in the works of the twelfth 

3« Op. cit., p. 234. 

3" Op. cit., p. 286. 

^^ Op. cit., p. 257. 

*•« Man.scr, Johann v. Rupella. Jahro. f. Ph. u. sp. Thcol., 1912. 

3« Op. cit., p. 231, p. 329. 

3« Op. cit., p. 329. 

3« Op. cit.. p. 281. 



THE SPECIES SENSIBILIS 79 

century. The psychical nature of sensation, on the other 
hand, appears prominently, so that we have here a theory 
of sensation which is typically psycho-physical. It fails 
in details, because of undue respect for authority, and by 
confusing Aristotle with his Arabian commentators. In 
spite of that, Bl. Albert the Great and St. Thomas added 
little more than clearness and precision to the species- 
theory as outlined by John de la Rochelle. 

ST. BONAVENTURE.—^t Bonaventure, another 
Franciscan and pupil of Alexander of Hales, may be 
regarded as the last great exponent of early Scholastic- 
ism. He, too, is inclined to compromise, for, '^he stands 
forth as a champion and promoter of tradition.'"^" To 
quote his own words : '^Non enim intendo novas opiniones 
adversare, sed communes et approbatas retexere. Nee 
quispiam aestimet quod novi scripti velim esse fabrica 
tor."^^^ If, furthermore, we bear in mind that he treated 
of philosophy solely to substantiate his theology, and that 
purely speculative discussions had no charm for him, 
then we are prepared to hear that he did not develop the 
theory of the species sensibilis. In fact, the physiology 
and physics of sensation, which had received so much 
attention from John de la Rochelle and from other pred- 
ecessors, were scarcely touched upon by St. Bonaven 
ture. The union of soul and body, the spiritus, the ex 
ternal medium, the passive character of sensation, — all 
these doctrines he defended according to the manner of 
Alexander of Hales and John de la Rochelle. 

St. Bonaventure, however, brings out more promi 
nently the characteristic views of St. Augustine. Body and 
soul ''in genere substantiae maxime distant ;"^^^ matter 
is ''prope nihil. "^^^ The soul is the form of the body, but 



350 De Wulf, op. cit., p. 283. 

361 Praeloc, ad II Sent. 

362 Brevil., P. II, c. 10. 

363 II. d. 12, a. 1, p. I. 



80 THE SCHOLASTIC THEORY OF 

besides that, says St. Bonaventure, it is ''hoc aliqnid.'"^* 
Then, too, we are told that knowledge is the " assimilatio 
cognoscentis ad cognoscibile, ""'^^ and this union is effected 
' ' secundum similitudinem quam anima abstrahit a re. ' '^^'^ 
*'Anima non cognoscit rem, nisi speciem ejus et formam 
sibi imprimat."^" Hence there is in all knowledge a 
passive element, a reception. 

In sensation there is always a passive and an active 
factor, a reception and a judgment. "Receptio est prin- 
cipaliter ratione organi, sed judicium ratione virtutis. "^^^ 
St. Bonaventure, therefore, states his view of the species 
sensibilis in these words : ' ' Nullum enim sensibile movet 
potentiam cog-nitivam, nisi mediante similitudine, quae 
egreditur ab objecto, sicut proles a parente, et hoc gen- 
eraliter, realiter, vel exemplariter est necesse in omni 
sensu. Ilia autem similitudo non facit completionem in 
actu sentiendi, nisi uniatur cum organo et virtute; et 
cum unitur, nova fit perceptio, et per illam perceptionem 
fit reductio ad objectum mediante similitudine ilia. Et 
licet non semper objectum sentiatur, semper tamen, quan- 
tum est de se, gignit similitudinem cum est in sua com- 
pletione. "^'^^ 

It is evident from this passage that St. Bonaventure 
considers the species as absolutely necessary for sensa- 
tion. What is the species? It is a likeness, a "simili- 
tudo" of the object, which proceeds from the object 
"sicut proles a parente." This comparison, "sicut 
proles a parente," might lead us to conclude that he con- 
sidered the species to be material, since it proceeds from 
a material object. We are confirmed in this impression 
when we read that bodies "quae habent aliquid de natura 
humida, aliquid de aerea, etc."^*^" enter the sense in sen- 



3M II. d. 17, a 


.1. P 


.. 2. 




^' Ibid. 








'^« Ibid. 








'" Ibid. 








'M II. d. 8, p. 


1, a. 


3. q. 


2. 


3^» De Reduc. 


Art. 


, n. 8 




'•'o It. Men. in 


D., 


c. 2. 





THE SPECIES SENSIBILIS 81 

sation. However, that we must interpret the former as 
an analogy, and the latter as merely pointing out the 
special objects of the senses, appears from other expres- 
sions which state explicitly that the species is "non 
de materia "^^^ and cannot be ' ' sensibiliter separari 
ab objecto."^*''- Nevertheless, though not material, the 
species is a true likeness or image produced by the object 
itself. ''Objectum . . . gignit similitudinem, " and 
this "similitudo" is '4n medio genita."^''^ 

The function of the species is to move, or reduce to 
action, the knowing faculty; ''movet potentiam cogniti- 
vam. " But we saw above: ''Anima . . . speciem ejus 
(rei) et formam sibi imprimat." Is, then, the soul the 
cause of the species, or does the object produce HI These 
apparent contradictions call to mind similar expressions 
in St. Augustine's works, and must evidently be inter- 
preted in a similar manner, namely, the object is the 
material or passive cause, the soul is the efficient or active 
cause of the species. In that light St. Bonaventure can 
with equal right say that the object produces the form, 
or, that the soul informs itself. 

Another result of the species is the union of object 
and subject: ''Fit reductio ad objectum medianto simili- 
tudine ilia." The species is not itself the object of sen- 
sation, the object known, but, "mediante similitudine, " 
the external object is known. Here, again, we are re- 
minded of St. Augustine: the species does not cause the 
object to be known, unless this be united to the organ and 
to the sense-faculty. The species is not sensation, but 
it is a necessary factor in sensation. - 

How is the union of the species with the sense brought 
about? St. Bonaventure tells us the species is "in medio 
genita et deinde ipsi organo impressa." But that it is 
conveyed by the action of the medium, as John de la 



»«i In Haexaem., col. XI, 23. 
»62 II. d. 8, p. 2, a. u., p. 3. 
'«3 It. Men. in D., c. 2. 



82 THE SCHOLASTIC THEORY OF 

Rochelle maintained, is not maintained by St. Bonaven- 
ture. He recognizes the difficulty of explaining how this 
takes place, in fact, he does not attempt to explain the 
how: '^Et hoc est mirabile. "^*'* Still he maintained that 
an immaterial likeness of the sense-object somehow must 
he conveyed by the medium to the sense. 

If John de la Rochelle was largely influenced by 
Arabian science and by the materialistic view of the 
species sensibilis, St. Bonaventure is influenced even 
more by the psychical aspect of St. Augustine. That 
alone accounts for the fact that Matthew of Aquasparta, 
a pupil of St. Bonaventure, accepted, in gloho, St. 
Augustine's theory of sensation.'*^^ 

In general it may be said that the early Franciscan 
school favored the new peripatetic philosophy, and con- 
sequently, also the psycho-physical aspect of the species 
sensibilis. But it seems they lacked the courage of their 
convictions, or else they were hampered by their devo- 
tion to tradition. They readily accepted the new philoso- 
phy when this did not entail the rejection of the old tra- 
ditional views ; but when the old and the new clashed, 
instead of accepting either outright, they attempted to 
compromise. As a result, their philosophy in general 
retains some of that looseness and indecision which char- 
acterized the philosophy of the early decades of the 
thirteenth century. 

THE EARLY DOMINICANS.— The relation of the 
early Dominicians to the new Aristotelianism was quite 
different from that of the early Franciscans. At Paris 
the early Dominicans accepted the traditional Augiistin- 
ian philosophy and theology throughout ; at Oxford they 
even actively opposed the rising peripatetic philosophy.^'^'^ 
But the great geniuses of the Order of Preachers, Bl. 



3M In Haexaem.. col. XI, 23. 
=«« Cf. De Wulf, op. cit., p. 291. 
366 De Wulf, op. cit., p. 296flF. 



THE SPECIES SENSIBILIS 83 

Albert the Great and St. Thomas Aquinas, overcame all 
opposition, and fixed upon their Order a philosophy 
which was more purely peripatetic than that of the Fran- 
ciscan school.^" 

History has been unjust to Bl. Albert. The greatness 
of St. Thomas, his pupil, has, in a measure, dimmed the 
luster of the master. And yet, as Haneberg observes,^^^ 
Scholastic philosophy has no representative in the West- 
ern world, whose knowledge is so comprehensive as that 
of the ''Doctor Universalis." He was conversant with 
the Sacred Scriptures, with the writings of the Fathers, 
and with the tradional theology and philosophy ; he sur- 
passed his predecessors in the knowledge of ancient 
Greek philosophy ; he was well enough versed in Arabian 
philosophy to distinguish it, at least in most cases, from 
Aristotle. Added to this, he possessed a thorough know- 
ledge of the natural sciences of his day. He failed to 
weld this immense wealth of accumulated knowledge into 
one consistent whole. "Aristotelianism, Neo-Platonism, 
Augustinianism, a philosophy developing independently 
from within, and a dominant theology : all are to be seen 
in their separate original forms in Albert, even where 
the blending process has already commenced. "^''^ How- 
ever, though we cannot speak of Albert's psychology as 
one system, neither can we speak of it as three or four 
distinct systems ; he attempted a synthesis but succeeded 
only in part."" " 

St. Thomas continued this work of synthesis. He 
surpassed his teacher, not so much in diligence and learn- 
ing, as in mental acumen, breadth of view, sequence of 
thought, and precision of expression.^" Concerning sen- 
sation, the subject of our investigation, the views of Bl. 



36^ Ibid. 

^^ Erkenntnisslehre d. Ibn Sina u. Albertus, p. 191. 

^ De Wulf, op. cit., p. 302, note. 

3™ De Wulf. op. cit., p. 302. 

3" Cf. Schneider, Die Psychol. Albertws d. Gr., p. 23. 



84 THE SCHOLASTIC THEORY OF 

Albert and St. Thomas are so nearly alike that we may 
well state them side by side, 

BL. ALBERT AND ST. THOMAS.— There can 
be no doubt that the influence of Aristotle is pre- 
dominant in the psychology of these two great Scho- 
lastics. Albert defends very clearly the substantial 
union of body and soul: "Anima est primus actus cor- 
poris physici potentia vitam habentis ; "^^'"^ ''ex anima et 
corpore fit unum naturaliter et substantialiter ; ""'• ''sub- 
stantiale decimus animae esse, quod sit actus cor- 
poris.""* Hence in his commentary on the Sentences he 
rejects the theory of an internal medium uniting soul 
and body."^^ 

Albert, however, looks upon the soul not only as the 
form of the body, but also as "motor corporis.""" As 
"actus primus," it determines the "esse" of the body; 
as "actus secundus," "conducit ipsum ad operati- 
onem.""^ In this second aspect the soul is united to the 
body by media ; that is, the interaction of soul and body 
is explained by media. Albert accepts two media in his 
"Summa Theologiae," on the authority of the "De 
Spiritu et Anima"; but he admits in the same context 
that we may accept four media, as did Alexander of 
Hales."* In the ' ' Summa de Creaturis ' ' he distinguishes 
between a "medium generale" and a "medium spe- 
ciale." There he attempts a peripatetic explanation ot 
the doctrine of the medium, so that its Augustiniau char- 
acter is almost lost.^" 

Albert's indecision concerning the medium is ac- 
counted for by the absence of any definite view in Aris- 



3'2 De An., II, t. 1, c. 5. 

3" S. Th., p. 2, t. 12, q. 69, m. 1. 

3'" S. de Creat., p. 2, t. 1, p. 4. 

3'6 L. I, d. 8. a. 26. 

="8 S. Th.. p. 2, t. 12. q. 68, ad 5. 

'" S. de Creat., p. 2, t. 1, q. 2, a. 3. 

3'» II. t. 13, q. 77, m. 2. 

"8 Cf. Schneider, op. cit., p. 389. 



THE SPECIES SENSIBILIS 85 

totle 's works regarding this doctrine. That Albert should 
waver with regard to a doctrine so fundamental shows 
the futility of his attempt to synthesize Aristotle and St. 
Augustine ; at the same time, it shows that the traditional 
Augustinianism was losing ground and giving way before 
the new peripateticism.^^^ 

St. Thomas is in perfect accord with these views of 
Bl. Albert the Great. He, too, speaks of a two-fold aspect 
of the soul and of an internal medium. ''Sicut corpus 
habet esse per animum, sicut per formam, ita et unitur 
animae immediate, inquantum anima est forma corporis. 
Sed inquantum est motor, nihil prohibet aliquid esse 
medium, prout una pars movetur ab anima, mediante 
alia."^®- Again we are told that warmth and moisture 
''cadunt media inter animam et corpus ut dispositi- 
ones. ' '^^^ The spiritus as medium between body and soul 
St. Thomas defines as ''vapor tenuis diffusus per mem- 
bra ad eorum motus;'"^* or again as ' ' subtilissimi va- 
pores, per quos diffunduntur virtutes animae in partes 
corporis. '"^^ The spiritus animalis, according to the 
Angelic Doctor, is "proximum instrumentum animae in 
operationibus quae per corpus exercentur. ' '^®*' 

If by a medium between body and soul is meant that 
one part of the body is moved by means of another part, 
this is not at all opposed to peripatetic principles. That 
warmth and moisture are necessary conditions for the 
interaction of soul and body is suggested by Aristotle 
himself. Finally, the idea of a spiritus as an instrument 
or means for the interaction of soul and body seems to 
be due, not to any metaphysical misconception but rather 
to a deficient physiology, to a faulty understanding of 
the function and anatomy of the nerves. 



^^1 Schneider, op. cit., p. 
382 De An., II, 1. 1. 
3'3 Q. u. de An., a. 16. 
^ Cg., IV. 23. 
2«« I. Sent., 10, 1, 4, c. 
3«6 IV. Sent.. 49. 3. 2, c. 



86 THE SCHOLASTIC THEORY OF 

St. Thomas contends that as the soul is the principle 
of all activity in the body, so ' ' aliquae partes animae sunt 
actus aliquarum partium corporis. '"^^ Hence he says: 
"Potentia (sensitiva) . . . est quasi forma organi. "^** 
And from this it follows "quod sentire non sit actus ani- 
mae tantum, sed conjuncti."^^** Bl. Albert expresses these 
same views in the comprehensive words: ''organa (sen- 
sus) autem sunt animata. "^'"' This is one of the prin- 
ciples upon which the psycho-physical aspect of the species 
sensibilis is based : the organs of the sense are animated ; 
and hence we cannot have a purely physical action of 
an object on the organ. Since the faculty of sense is 
"quasi forma "^''^ of the organ, every impression upon 
the organ is at the same time physical and psychical, or, 
psycho-physical. This theory does away with the materi- 
alism of the Arabians as well as with the subjectivism 
of the Augustinians. 

St. Thomas defines the faculty of sensation as "quae- 
dam potentia passiva, quae nata est immutari ab ex- 
teriore sensibili. "^^^ What he means by a "potentia 
passiva, ' ' we learn from the following : ' ' Potentia activa 
comparatur ad suum objectum ut ens in actu ad ens in 
potentia; potentia antem passiva comparatur ad suum 
objectum e converso ut ens in potentia ad ens in actu."^*^ 
In other words, then, the sense is a faculty which must 
be stimulated from without, in order that it become 
active. The sense is not purely passive ; it is active, 
though only after it has been aroused by an impression 
from without. The senses are called passive, according 
to St. Thomas, "quia per sensibilia objecta moventur et 
fiunt in actu. ' '^®* 



»" De An., II, 1. 2. 

«« De An.. II. 1. 24. 

'8» S. theol., I. q. 84. a. 6. 

"» De An., t. c. 3, 1. 

'»' S. de Creat., p. 2. t. I, q. 2, a. 5 

3»2 S. theol., 1. q. 87, a. 3. 

MS S. theol., I. q. 79. a. 7. c. 

»»^ Verit.. q. XVI. a. 1. ad 13. 



THE SPECIES SENSIBILIS 87 

Albert, too, insists upon the passive character of sen- 
sation and explains it in the same manner. Sensation is 
a ''potentia passiva" which becomes actually sentient in 
the presence of a sensible object, "quod agit in ipso 
(sensu) formam suam, ut illam sentiat in actu."^®^ The 
object is, so to say, the complement of the sensitive fac- 
ulty without which the sense is not actually sentient. Of 
itself no more than "privatio et materia ad sensi- 
bilia,"^^® the sense becomes active when ''completus per 
actum speciei sensitivae. "^^^ 

But in a similar man&er the sense is the complement 
of the object. The same stimulus which causes the sense 
to perceive, causes the object to be perceived. Unless the 
sense be aroused to actuality, the object is not actually 
perceived; in fact, a thing is not the actual object of 
sensation, except when the sense is aroused to perceive 
it.^^^ Hence St. Thomas says : ' ' Sensus in actu est sensi- 
bile in actu . . . quia ex utroque fit unum, sicut ex actu 
et potentia. ' '^^'^ One and the same act makes both the ob- 
ject and the subject of sensation actual, but, as Albert 
says, ''est (actus) sensibilis ut agentis, et sensitivi ut 
recipientis et patientis. ' '*°*' 

The nature of this "passio," or of this change in the 
sense, is not, Albert contends, that of a physical change, 
*'de contrario in contrarium;" it is a change "de pri- 
vatione in habitum."*"^ The sense is called a passive 
faculty, "non quod recipiat formam quae transmutat sub- 
stantiam suam in substantiam secundum esse, sed potius 
transmutatur in speciem sensibilem secundum intenti- 
onem. ' '*°^ In these words, again, the view of the Arabians 
is rejected. They affirmed what Albert here denies; 



»95 S. de Great., p. 2. q. 34. a. 1. 
396 Op. cit.. q. 33. a. 1. 
^^ Op. cit., q. 34, a. 1. 

398 Ibid. 

399 S. theol., I. q. 55, a. 1. 

«"> S. de Great., p. 2, q. 34. a. 1. 
«« S. de Great., p. 2, q. 21, a. 5. 
«2 0p. cit.. q. 34, a. 1. 



88 THE SCHOLASTIC THEORY OF 

namely, that sensation is a change *'de contrario in con- 
trarium, ' ' and that the sense receives a form which causes 
a physical and chemical change in the sense-organ. 

St. Thomas formulates in this connection one of his 
comprehensive metaphysical principles : ' ' Dicitur aliquis 
pati communiter ex hoc solo quod id quod est in potentia 
ad aliquid, recipit illud ad quod erat in potentia, absque 
hoc quod aliquid abjieiatur ; secundum quem modum omne 
quod exit de potentia in actum potest dici pati, etiam cum 
perficitur. ""^ When, therefore, St. Thomas speaks of the 
passive character of sensation, he does not mean that 
the sense suffers the loss of anything; on the contrary, 
he means to say that the sense is perfected by becoming 
actually what it already was potentially. Change in the 
ordinary meaning of the word, St. Thomas calls "im- 
mutatio naturalis," "secundum quod forma immu- 
tantis recipitur in immutato secundum esse naturale.""* 
This, he tells us, takes place in all sensation except in 
sight. But this is not sufficient; otherwise any influence 
of one thing upon another would imply sensation. Be 
sides the ''immutatio naturalis," ''the immutatio spiritu- 
alis," ''secundum quod forma immutantis recipitur in 
immutato secundum esse spirituale, "^°^ is necessary for 
sensation. Albert says: "Immutatio aeris non sufficit ad 
visum ; sed oportet etiam species visibiles in oculum pro- 
cedere ad actum secundum actum lucidi."*°^ 

If we ask why this "immutatio spiritualis" is neces- 
sary, St. Thomas tells us: "Oportet enim omne agens 
conjungi in quo immediate agit, et sua \drtute illud con- 
tingere.""^ But in every act of knowledge the object acts 
upon the cognitive faculty; hence the object must in 
some way be united to the subject. "Cognitio omnis fit 
per hoc, quod cognitum est aliquo modo in cognoscente, 



*'>^ S. theol., I. q. 79, a. 2. 
*°* S. theol., 1. q. 78, a. 3. 
«» Ibid. 

«o« S. de Creat., p. 2, q. 22. 
"" S. theol., I. q. 8, a. 1. 



THE SPECIES SENSIBILIS 89 

scilicet secundum similitudinem. Nam cognoscens in 
actu est ipsum cognitum in actu."*°® Or, as Albert ex- 
presses the same thought: '^Omne apprehendere est ac- 
cipere formam apprehensi, non secundum esse quod habet 
in eo quod apprehenditur, sed secundum quod est intentio 
ipsius et species. "*°^ The reason for this is in the very 
nature of knowledge which is a perfection of the subject, 
and not of the object. St. Thomas says : ' ' Cognitio non 
dicit effluxum a cognoscente in cognitum, sicut est in 
actionibus naturalibus, sed magis dicit existentiam cog- 
niti in cognoscente."*^" If this be true of knowledge in 
general, then, too, it is true of sensation; for sensation 
is the source of all knowledge. St. Thomas affirms this 
in the words: ^'Scientiam a sensibilibus mens nostra 
accipit. ' '*" 

The object of sensation must, therefore, be united to 
the sense in some manner, and by this union, reduce the 
sense to actuality. The object cannot be united to the 
sense, or be present in the sense, "secundum esse na- 
turale," because the one is material and the other is im- 
material. Hence the object must be in the sense ' ' secun- 
dum esse spirituale." "Non enim fit visio in actu," 
we read in St. Thomas, "nisi per hoc quod res visa 
quadammodo est in vidente. Et in rebus quidem corp- 
oralibus apparet quod res visa non potest esse in vidente 
per suam essentiam, sed solum per suam similitudinem ; 
sicut similitudo lapidis est in oculo, per quam fit visio in 
actu; non autem ipsa substantia lapidis."*^" In the words 
of Albert : ' ' Omnis sensus est susceptivus speciernm sine 
materia. ' '*^^ 

What is this "esse spirituale," this species of the 
object! Listen to St. Thomas: "Illud quod est prin- 



^"s De An., II, 1. 12. 

*^ De An., II, t. 3, c. 4. 

«» Verit., q. II, a. 5, as 15. 

«" Verit., q. X, a. 6. 

"2 S. theol., I. q. 12, a. 2. 

♦" S. de Great., p. 2, q. 34, 



90 THE SCHOLASTIC THEORY OF j 

cipium essendi est etiam principium cognoscendi ex parte 
rei cognitae, quia per sua principia res cognoscibilis I 
est, sed illud quo cognoscitur ex parte cognoseentis, est 
similitudo rei."*^* ''Sicut res habet esse per propriam 
formam, ita virtus cognoscitiva habet cognoscere per 
similitudinem rei cognitae. "*^^ Objectively, therefore, the 
species, according to St. Thomas, is the form of the object, 
which is the "principium essendi;" but subjectively, the 
species is an image or a likeness of the object. It is a 
vital or intentional similitude of the object in the sense 
which, by this very modification, passes from the potency 
to the act of knowledge. Entitatively, the species sensi- 
bilis is a vital modification of the knowing subject, of the 
sense, and nothing more; but representatively , it is the 
form of the object. Or, again, we may regard sensation 
as the terminus of a double principle, of which the species 
sensibilis is the formal determinative principle, "deter- 
minant cognitionnel,"*" giving the intonation, so to say, 
and the sense is the material principle or the natural 
substratum of the process of sensation.*^^ 

We may say, then, that the form of the object is in 
the sense, but not with the same mode of being as it is in 
the object. As St. Thomas expresses it: "Forma sensi- 
bilis alio modo est in re quae est extra animam, et alio 
modo in sensu qui suscipit formas sensibilium absque 
materia. . . . Nam receptum est in recipiente per 
modum recipientis. "*^* Albert, too, informs us that iiie 
species is not the form of the object "prout est in ipso 
sensibili . . . sed intentio ejus;" however, "signum 
facit de re et notitiam." The object exists, indeed, in its 
natural "esse," in the medium of sensation and in the 
sense; but "in objecto habet esse materiale; in sensu 
habet esse spirituale; in medio habet esse sensibile."*'' 



«* Verit., q. II, a. 3, ad 8. 

"^ Q. u. de An., a. 5 c. 

*^^ Mercier, Psychologio, I., p. Hi. 

"' Lanna, Le Teoria della corioscenza, p. 46. 

"8 S. theol., q. 84, a. 1 . 

"» S. de Great., p. 2. q. 3t. a. «. 



THE SPECIES SENSIBILIS 91 

The ''esse spirituale" of the object is not ''proprie imago 
vel forma (ejus), sed species imaginis vel formae."*^° 

The species sensibilis, as Albert the Great and St. 
Thomas present it, is evidently not material. It is the 
''esse spirituale" of the object; its function is to effect 
a union between the material object and the immaterial 
sense. If, then, the species itself were material, the 
problem of uniting matter to spirit would still remain. 
Hence St. Thomas says: "Sensus est susceptivus speci- 
erum sine materia, sicut cera recipit sigTium annuli, sine 
ferro et auro."^^^ Albert, too, is explicit when he treats 
of this. "Omni sensui convenit ipsum esse susceptivum 
sensibilium specierum, sine materia et esse materiale, 
materia tamen praesente."*^^ These last words, "materia 
tamen praesente," suggest that the species, though not 
material, represents the material object. St. Thomas ob- 
serves that the sense, indeed, receives the form of the 
object without the matter, "sed cum materialibus condi- 
tionibus ; "*^^ Albert says, "cum appendiciis materiae." 
Hence sensation implies the apprehension of an object 
"in individuo," i. e., as it exists in nature with all the 
individuating conditions of matter. 

The species sensibilis must be considered immaterial, 
because we learn from St. Thomas that the species re- 
ceives, indeed, its representative nature from the material 
object, but its entitative nature from the soul. "Anima 
humana similitudines rerum, quibus cognoscit, accipit a 
rebus illo modo accipiendi, quo patiens accipit ab agente, 
quod non est intelligendum, quasi agens influxit in patiens 
eamdem numero speciem, quam habet in seipso, sed gen- 
erat sui similem, educendo de potentia in actum, et per 
hunc modum dicitur species coloris deferri a corpore 
colorato ad visum. ' '-'* 



*20 Op. cit., q. 21, a. 3. 
«i De An., II, 1. 24. 
<22 De An., II, t. 4, c. 1. 
^23 S. theol., I. q. 84, a. 2. 
«^ Quodlib., VIII, q. 2, a. 



92 THE SCHOLASTIC THEORY OF 

The species sensibilis, finally, is not the object of 
sensation, the object directly known; it is the "principium 
cognoscendi rem visivam," as Albert says.*" But if the 
species is the principle of knowledge, or that by which an 
object is known, then it cannot itself be the object known. 
The immediate object is the "rem visivam"; the species 
is the means by which or in which the object, the "rem 
visivam, ' ' is known. In the words of St. Thomas : ' ' Spe- 
cies visibilis non se habet ut quod videtur, sed ut quo 
videtur."*-^ The species is a postulate of reason, of 
which the sense is not even aware: "Oculus videns rem 
per speciem, non videt ipsam speciem in eo apparen- 
tem."*" Hence the species is the principium quo co- 
gnoscendi and not the principium quod. 

How does the species sensibilis originate? How does 
the influence from the object, which causes the species to 
arise in the sense, come in contact with the sense! This 
Bl. Albert and Great and St. Thomas explain by the exter- 
nal medium of sensation. After discussing the nature of 
each medium and the nature of its action according to the 
science of his day, Albert tells us that the medium does 
not convey the "objectum sensibile" as it exists in the 
object; otherwise, color, for instance, would act in the 
medium, would color the medium. Hence the "sensi- 
bile" has a mode of being in the medium, different from 
its mode of being in the object: "In objecto enim habet 
esse materiale; ... in medio vero sensibile,"*^® This 
he claims for the "objectum sensibile" of sight, which is 
in the medium only ' ' in potentia . . . sicut in transitu et 
in via."*"'' The "objectum sensibile" of hearing 
and of smell is, indeed, in the medium "ut in materia, in 
ipso est actu"; but it acts upon the sense, not" actionema- 
teriae, sed actione medii. ' ' The ' ' sensibilia ' ' of taste and 



«s S. de Creat., p. 2, q. 21, a. 5. 
«6 De Spir. Creat., a. 9, ad 6. 
«7 De Sens., 1. 4. 
'28 S. de Creat., p. 2, q. 34. a. 2. 
«" Ibid. 



THE SPECIES SENSIBILIS 93 

touch, which have no external medium, are ' ' actu . . . et 
in objecto, et in medio, et in organo." These, then, receive 
their '^esse spirituale" "per spiritum animalem attra- 
hentem et deferentem intentiones ipsorum sensibilium 
ad cerebrum. . . . Per hoc patet, quod intentio calidi per 
spiritum attractivum animalem ab origine tactus non 
calef acit cerebrum. ' '*^° 

St. Thomas, likewise, contends that the ''sensibile" is 
not in the medium as it is in the object. ' ' Color est quidem 
in corpore colorato sicut qualitas completa in suo esse 
naturali ; in medio autem incompleta secundum quoddam 
esse intentionale."*" In fact, he maintains the '^sensi- 
bile" is not impressed upon the medium, but so affects the 
medium that the latter will impress a species of the object 
upon the sense. ' ' Dicendum est quod ab odorabili resolvi 
quidem potest fumalis evaporatio, quae tamen non per- 
tingit usque ad terminum ubi odor percipitur, sed immu- 
tatur medium spiritualiter, ultra quam dicta evaporatio 
pertingere possit."*^- Here St. Thomas expresses clearly 
that the species sensibilis is something over and above the 
impression of physical qualities. 

Concerning the medium of taste and touch, St. Thomas 
says: "A^idetur se habere caro et lingua ad organum 
sensus tactus, sicut se habent aer et aqua ad organum 
visus."*^* The only difference between them, according 
to the Angelic Doctor, is that we perceive the objects of 
sight, hearing, and smell "per hoc quod movent medium 
et iterum medium movet nos"; and we perceive the ob- 
jects of taste and touch "per medium extraneum, non 
quasi moti a medio extraneo, sed simul cum medio move- 
mur a sensibili."*^* 

Eeturning to Albert, we learn that the "objectum 
sensibile" is generated in the medium by the form of the 



«» Ibid. 

«' De Sens., 1. 5. 
"2 De An., II, 1. 20. 
«3 De An., II, 1. 23. 
«* Ibid. 



94 THE SCHOLASTIC THEORY OF 

object. To ask liow this is possible, is like asking "quid 
conf erat luci lucere secundum actum. ' '*^^ The form of the 
object is a "virtus activa" which acts "sine aliquo motivo 
extrinseco " ; " et sic omnis forma multiplicat intentionem 
suam."^'^ 

Neither can it be objected that a material form cannot 
produce this "esse" of the "sensibile," which is "multo 
spiritualius quam ipse aer sit."*"'^ The "objectum sen- 
sibile" is generated in the medium by the form of the 
object "eo quod est in potentia esse formalis et efifici- 
entis," and not "eo quod est in potentia esse materi- 
alis."*^" The degree of the spirituality of the "sensibile" 
in the medium differs, "quia spiritualius esse est coloris 
in medio quam soni; et iterum spiritualius esse est soni 
in medio quam odoris."*^^ Albert proves this by referring 
us to the wind, which does not disturb color, but which 
disturbs sound and even removes odor. 

The movement of the medium by which this "sensi- 
bile" is carried to the sense varies with the several 
senses. Color is brought to the eye by the motion of 
light in the transparent. But "motus lucis in diaphano 
subito est, et non in tempore." And yet Albert goes on 
to tell us "non est ibi proprie motus, nee alteratio, nee 
loci mutatio, sed generatio potius in omnibus partibus 
medii directe oppositis distantibus secundum propor- 
tionem secundum quam potest in immutabile visibile. ""'' 
Sound is generated in the air immediately surrounding 
the object; this air then moves a further part of air, and 
so on, till sound is actually present in every part of the 
medium "usque ad auditum."^*^ Odors are brought to 
the sense with air or water " evaporatione et permu- 
tatione.""' 



«s De An., II, t. 3, c. 6. 

«« Ibid. 

«' Ibid. 

*^ De An., II. t. 3, c. 6. 

«8 Ibid. 

<« S. de Creat., p. 2, q. 21, a. 4. 

«i Op. cit., q. 24, a. 5. 

*^ Op. cit.. q. 30. 



THE SPECIES SENSIBILIS 95 

But Albert told us above that the ^'sensibile" ''in 
sensu habet esse spirituale tantum. "^"^ How is this ef- 
fected ? The ' ' sensibile ' ' acts directly upon the organ of 
sense; "organa autem sunt animata." The sense is 
affected only "actione medii," not "actione ma- 
teriae." For instance, color does not affect the sense of 
sight, "nisi actu lucidi;"*** the auditory nerve is affected 
"ex aere percutiente et sonante per hunc modum, . . . 
sed non de necessitate immutatur nisi secundum sonum, 
. . . quia sensus recipit sensibiles species sine 
materia. ' '**^ 

St. Thomas informs us that the species is received 
by the organ of sense. But the organ and faculty of 
sense are "idem subjecto. "**^ Hence the sense "est co- 
gnoscitivus sensibilis sui objecti, cujus species fit in suo 
organo, inquantum est tale organum. ' '**^ The manner in 
which the species is impressed upon the sense-organ 
varies. In touch and taste it takes place "per contae- 
tum;" in smell, "cum aliqua resolutione odorabili;" in 
hearing, "cum aliquo motu locali," and in sight, "absque 
immutatione sensibili, sed per solam immutationem 
spiritualem medii et organi."**^ 

The sense is disposed to receive the species, according 
to Albert, "per spiritum animalem et calorem natur- 
alem et harmoniam organi."**^ It is actually sentient 
"quando habet speciem sensibilem, "^^'^ because "ab 
intentionibus sensibilium quae sunt in medio moventur 
sensus."*" 

The sense-organ must be proportionate to the * ' sen- 
sibile" as this exists in the medium. Albert introduces 



«3 Op. cit., q. 34, a. 2. 

«^ Op. cit., q. 21, a. 5. 

«5 Op. cit., q. 24, a. 2. 

«« De An., II, 1. 24. 

«' De An., Ill, 1. 3. 

<« De An., Ill, 1. 1. 

<^9 S. de Great., p. 2, q. 24, a. 1. 

«» Ibid. 

«i De An., II, t, 3, c. 16. 



96 THE SCHOLASTIC THEORY OF 

a very complete anatomy of the various sense-organs 
and of the brain and nerves, all of which is largely tele- 
ological. He prefers the anatomy of the Arabians to that 
of Galen whenever they differ. Then, too, he informs 
us that the spiritus is important as a means of conveying 
the species from the sense-organ to the brain. This is 
particularly true with regard to taste and touch, which 
have no external medium.*^- 

In the ''De Anima" Albert rejects Democritus' theory 
of vision.^'^^ In the "De Sensu"*^* he rejects as ridiculous 
the theory of those who would call light the common 
active element in all sensation, analogous to the '4ntel- 
lectus agens" in intellection. But he speaks with more 
reserve about the theory of Plato and St. Augustine: 
''Sine praejudicio aut ego non intelligo eos, aut ipsi 
falsum dixerunt. "*^^ St. Thomas maintains the object of 
sensation is united to the sense "non per modum de- 
fluxionis, ut Democritus posuit, sed per quandam opera- 
tionem."*^*^ The species, therefore, arises from the action 
of the object and not from its "esse," but the nature of 
this ' ' operatio ' ' St. Thomas does not determine. 

It appears from this that Bl. Albert the Great and 
St. Thomas Aquinas bring out in bold relief the psycho- 
physical aspect of the species sensibilis. In the earlier 
philosophers of the thirteenth century this view of the 
species was not so distinctly outlined. In fact, we have 
observed that Alfred of Sareshel inclined towards the 
materialistic view, whereas William of Auvergne seemed, 
at times, to favor the psychical view. Still we have 
classed these, too, with the philosophers who accepted 
the psycho-physical aspect, on the principle that the 
influence of Aristotelian psychologj^ is the distinctive 
mark of this aspect. After all, Bl. Albert and St. Thomas 



*** Cf. Schneider, op. cit., p. 

'M II, t. 3, c. 9. 

•" T. 3. c. 1. 

*^ De An., II, t. 3, c. 6. 

♦"« S. theol.. I. q. 84. a. 6. 



THE SPECIES SENSIBILIS 97 

owe their preeminence among the philosophers of the thir- 
teenth century, not to the originality of their thoughts, 
nor to their constructive and creative powers, but to 
their powers of synthesis, of systematizing the philosophy 
of the Middle Ages. Thus, in the introductory chapter, it 
was observed that the Aristotelian elSos -theory is based 
on the several doctrines of matter and form, of the sub- 
stantial union of body and soul, and of potency and act. 
Now William of Auvergne and John de la Rochelle ac- 
cepted these fundamental doctrines as unreservedly as 
did Bl. Albert or St. Thomas. Where these differ from 
their predecessors is in the precise comprehension of 
those doctrines, or in the extent of their application: a 
difference in development and perfection, indeed, but 
not a difference of view. All admitted the substantial 
union of body and soul, but it was left to Bl. Albert and 
St. Thomas to apply this doctrine and draw the inference 
that, therefore, the organs of sense are animated. Again, 
the philosophers of the early thirteenth century insisted 
that the species sensibilis is immaterial, but they found 
difficulty in defending this, since they regarded the spe- 
cies as something outside of the sense, impressed upon 
the material medium by a material object. St. Thomas 
then explained that the species is not impressed upon the 
medium, but the medium is so affected by the object, as 
to impress upon the sense a species of the object ; hence 
the species is entitatively a modification of the sense and 
has no existence apart from the sense. The passive 
nature of the sense, too, was conceded by some philoso- 
phers of the twelfth century; but St. Thomas was the 
first to define a passive faculty with accuracy and clear- 
ness, was first to point out that a passive faculty receives 
from without, not the object of its activity, but merely the 
stimulus to action. 

Compared with the materialistic aspect of the species 
sensibilis, the psycho-physical presents a change of view- 
point, a difference of kind, and not of degree only. In 



98 THE SCHOLASTIC THEORY OF 

the former we saw a faulty concept of form which was the 
source of much confusion ; there we saw the physical and 
physiological factors of sensation emphasized so unduly 
that the psychical factor was almost excluded ; there, too, 
we saw the physical impression on the sense-organ looked 
upon as the direct object of the sense-faculty. But all 
that is foreign to the psycho-physical aspect. At the same 
time, the subjectivism, the pure speculation, which dis- 
tinguished the psychical view, is avoided in the psycho- 
physical aspect of the species sensibilis as presented by 
the great Scholastics of the thirteenth century, which is, 
indeed, a return to the ever-famous elSos-theory ot 
Aristotle. 



CONCLUSION. 

The history of the theory of the species sensibilis from 
St. Augustine to St. Thomas is indicative of the develop- 
ment of Scholasticism during its formative period. Based 
on the idealism and subjectivism of St. Augustine, the 
Scholastics before the twelfth century" developed dialec- 
tics and pure metaphysics. Thereupon, realizing the 
fruitlessness of their speculations, they welcomed the 
new learning of the Arabians, which was based on obser- 
vation rather than on speculation, and which, conse- 
quently, favored materialism rather than idealism. But as 
in the history of all human thought extremes beget their 
opposites, so in this case. In the twelfth century the nat- 
ural sciences and the human arts were fostered to the ne- 
glect of what is today called philosophy. In consequence 
thereof, scientific knowledge outdistanced metaphysics; 
facts and phenomena of nature were observed, but meta- 
physics could not explain them. Thus the stage was set 
for the entrance of a philosophy which would account for 
the ultimate causes of things of sense. At this psycho- 
logical moment the works of Aristotle were introduced 
into the "Western world. Thenceforward the develop- 
ment of Scholasticism consisted in the more and more 
perfect adjustment of all knowledge according to Aris- 
totelian principles. This, of course, provoked the oppo- 
sition of conservative minds, but the struggle resulted, 
as such a struggle could only result, in the final accept- 
ance of Aristotle, modified in part by the traditional 
philosophy of Plato and by the individual thought of the 
great Scholastics of the thirteenth century. 

We have observed an analogous development in the 
history of the species sensibilis. The psychical view of 
this theory, which was subjective and purely speculative, 
remained uppermost till the twelfth century. Then, with 
the introduction of Arabian philosophy, the materialistic 



100 THE SCHOLASTIC THEORY OF 

aspect came into prominence, and continued so, till, 
through the influence of Aristotelian psychology and 
metaphysics, it was superseded by the psycho-physical 
view. 

That the Scholastic theory of the species sensibilis 
is primarily a metaphysical theory would, then, appear 
even from its parallel development with that of general 
metaphysics. But apart from this, we have seen that 
St. Augustine, and those who accepted his view, defended 
the species-theory solely on metaphysical principles, as 
a postulate of reason. Later on, indeed, the physical and 
physiological factors of sensation were emphasized 
almost to the exclusion of the psychical and metaphysical 
elements. When, however, the struggle between science 
and metaphysics, between observation and speculation, 
was adjusted by the Scholastics of the thirteenth century, 
then, again, the metaphysical character of the species- 
theory was brought into prominence. The physical and 
physiological phenomena that accompany the origin of 
the species were not neglected by the exponents of the 
psycho-physical aspect of the species; they were dis- 
cussed, but only in so far as they served to explain the 
metaphysical principles of the species-theory. 

We may, therefore, reject the physics and the physi- 
ology of the Scholastics, if this be necessary in the light 
of modern science. But as the metaphysics of sensation, 
the species sensibilis is neither superfluous nor ridiculous. 
For, as long as we admit that mind and matter are not 
identical, that our senses give us an objective knowledge 
of the external material world, and that all knowledge 
implies a union of some sort between the subject and the 
object of knowledge, so long, too, reason will demand 
some theory to explain the union between the external 
material object and the immaterial sense. As long as 
we admit that our senses are not purely active faculties, 
that our knowledge of the external world is not innate, 



THE SPECIES SENSIBILIS 101 

and that a stimulus from without causes our senses to 
act, so long, too, reason will demand some theory to 
explain the affection of an immaterial sense by a material 
object. This two-fold explanation is offered by the 
species-theory ; it is precisely the function of the species 
sensibilis to unite object and sense, and to arouse the 
sense to activity. 

Nevertheless, no element of the Scholastic theory of 
sensation has given rise to more criticism than the theory 
of the species sensibilis. Reid*" and Haureau*^^ contend 
that this theory implies the representative view of sen- 
sation; in other words, that the Scholastics considered 
the species to be the direct and immediate object of 
sense-knowledge, from which we conclude indirectly to 
the external object. Siebeck maintains*'^" that the Scho- 
lastics misunderstood the el8 -theory of Aristotle and, 
as a result, introduced into the species-theory some ma- 
terialistic elements from Democritus' etSwXoi^-theory. 
This second objection to the species sensibilis has become 
so general, that Eisler restates it in his excellent" Philoso- 
phisches Worterbuch." As was pointed out in Chapter 
II., both of these objections are well founded if applied 
to some defenders of the materialistic aspect of the 
species. There, too, it was shown that enthusiasm for 
Arabian philosophy is directly responsible for these 
erroneous views. But from Chapter III. it appears that 
those who brought Scholastic philosophy to its highest 
development, and who are recognized by everyone as the 
best representatives of this philosophy, reject in explicit 
terms the above-mentioned errors of earlier Scholastics. 
To say that St. Thomas, for instance, defended the species 
as the direct object of sensation, or that his theory of the 
species sensibilis is " halbmaterialistisch, "*®^ is wholly 



"^ Essays on the Intel. Faculties of Man, II, c. VIII. 

*^ Op. cit., I, p. 272. 

«» Gesch. d. Psychol., F, p. 432. 

«o Siebeck, Gesch. d. Psychol., P, p. 433. 



102 THE SCHOLASTIC THEORY OF 

unwarranted; anyone who has seriously studied the 
thought and expression of the Scholastics must come to 
this conclusion. 

To sum up, we may apply to the Scholastic theory 
of sensation, of which the species sensibilis is the most 
characteristic feature, the words which Siebeck applies 
to Aristotle's theory of sensation: "Das erkenntniss- 
theoretische Problem ist in derselben tiefer ergriffen, 
als es in der Regel heute auf diesem Gebiete geschieht. 
. . . So wenig auch fiir uns heute damit gesagt sein 
mag, der Act der Seele im Vorgange der Empfindung 
sei anzusehen als eine Ueberfiihrung aus dem Zustande 
der Realpotenz in die Verwirklichung dessen was in 
dieser von Haus aus angelegt ist, oder, in der Empfindung 
iibertrage sich die Form des Gegenstandes ohne die 
Materie in die Seele, ... so sind wir docli, abgesehen 
von unserer genaueren Kenntniss der physiologischen 
Vorgange, auch jetzt noch hinsichtlich des letzten 
Wesens der Empfindung nicht weitergekommen als zu 
der Antwort, die Empfindung sei nicht bloss ein recep- 
tives Erleiden des Eindruckes, sondern eine durch 
denselben bedingte Bethatigung der "Seele," durch 
welche die Empfindung als Bewusstseinsakt erst 
entstehe."'*'^ 



«i Gesch. d. Psychol., P. p. 39. 



BIBLIOGEAPHY. 

Abelard, Opera. Migne, P. L., vol. 178. 

Adelabd of Bath, Quaestiones naturales. Fragments in Jourdain's Recher- 

ches critiques. 
Adloch, B., Roscelin u. St. Anselm. 
Philos. Jahrb., 1907. 

Praefationes ad artis scholasticae inter occidentales fata. Brunae, 
1898. 
Alanus ab Insults, Opera. Migne, P. L., yoI. 210. 
Albertus Magnus, Opera Omnia. Lyons, 1890. 

Alcher of Clairvaux, Lib. de Spiritu et Anima. Migne, P. L., vol. 40. 
Alcuin, Opera. Migne, P. L., vols. 100-101. 

Alexander of Hales, Summa universae theologiae. Venet., 1576. 
Alfred of Sareshel, De Motu Cordis. Barach's Bibliotheca philosophor- 

um mediae aetatis. 
Anselm of Canterbury, Opera. Migne, P. L., vol. 155. 
Augustine, Opera. Migne, P. L., vols. 32-47. 
Bach, J., Die Erkenntnisslehre d. Alb. Magnus. Wien, 1881. 
Bacon, R., Opus Majus. Oxford, Bridges, 3 vols., 1897-1900. 
Baeumker, C, Die Impossibilia d. Siger v. 

Brabant (Beitrage). Munster, 1898. 

Witelo (Beitrage). Munster, 1908: 

Wilhelm von Conches. Kirchenlexikon, Bd. 12, 1901. 

Handschriftliches z. d. Werken d. Alanus. Fulda, 1894. 

Alfredus Anglicus. Arch. f. Gesch. d. Philos., Bd. 10. 

Die europaische Philos. d. Mittelalt. Die Kultur d. Gegen- 

wart, Berlin, 1909. 
Die Stellung d. Alfred v. Sareshel. Sitzungsber. d. miinch. 

Akad. d. Wiss., 1913. 
AvencebroIIs Pons Vitae (Beitrage). Munster, 1892-95. 
Dominicus Gundissalinus als philos. Schriftsteller. Miin- 
ster, 1900. 
Barach, S., Bibliotheca philosophorum mediae aetatis, 2 vols., Innsbruck, 

1876-78. 
Bardenhewer, O., Liber de Causis. Freiburg, 1882. 
Bauer, H., Die Psychologie Alhazens (Beitrage). Munster, 1911. 
Baumann, J., Alhazen. Ztschr. d. deutsch-morgenl. Gesellsch., Bd. 36. 
Baumgartner, M., Die Philos. d. Alanus de Insulis (Beitrage). Munster, 
1896. 
Die Erkenntnisslehre d. Wilhelm v. Auvergne (Beitrage). 
Munster, 1893. 
Baur, L., Dominicus Gundissalinus De divisione Philosophiae (Beitrage). 

Munster, 1903. 
Bede, Opera. Migne, P. L., vols. 90-95. 

Bernardus Silvestbis, De mundi universitate. Fragments in Barach's 
Bibliotheca. 

103 



104 THE SCHOLASTIC THEORY OF 

Bebthatjd, a., Gilbert de la Porree. Poitiers, 1892. 

Berthelot, M., La chimie au inoyen-S,ge. Paris, 1893. 

DE Boer, T., Gesch. d. Philos. im Islam. Stuttgart, 1901. 

BoETHius, Opera. Migne, P. L., vols. 90-95. 

BoNAVENTURE, Opera Omnia. 10 vols., Quaracchi, 1902. 

BouRGEAT, J., Etudes sur Vincent de Beauvais. Paris, 1856. 

BuLOW, G., Des Dominicus Gundissalinus Schrift iiber d. Unsterblichkeit d. 

Seele (Beitrage). Munster, 1896. 
Casstodorus, Opera. Migne, P. L., vols. 69-70. 
Catholic Encyclopedia, 15 vols.. New York, 1907-1914. 
Church, G., Saint Anselm. London, 1870. 
Clerval, a., Les ecoles de Chartres. Chartres, 1895. 

CoRRENS, P., Die d. Boethius falschlich zugeschriebene Abhandlung d. 
Dominicus Gundisalvi de unitate (Beitrage). Munster, 
1891. 
Cousin, V., Ouvrages inedits d'Abelard. Paris, 1839. 
Fragments philosophiques. Paris, 1850. 
Fragments de philos. du moyen-S.ge. Paris, 5. ed., 1865. 
Delaunay, D., St. Thomae de origine idearura doctrina. Paris, 1876. 
Denifle, H., Die Universitaten d. Mittelalt. Berlin, 1885. 
Deutsch, S., Peter Abelard. Leipzig, 1883. 
DiELS, H., Die Fragmente der Vorsokratiker. Berlin, 1906. 
Dieterici, F., Philosophic d. Araber. 8 vols., Leipzig, 1858-79. 
Domanski, B., Die Psychologic d. Nemesius (Beitrage). Munster, 1900. 

Die Lehre d. Nemesius iiber d. Wesen der Seele. Miinster, 
1897. 
DoMENicHELLi, F., Giovanui della Rochelle. Prato, 1882. 
DoMET DE VoRGES, E., Saint Anselm. Paris, 1901. 

La Perception et la psychologic thomiste. Paris, 
1892. 
DoNAT, J., Psychologia. 3. ed., Innsbruck, lOl^. 

Ehrle, F., Gesch. d. Franziskanerordens. Arch. f. Litt. u. Kirchengesch. d. 
Mittelalt., Bde. 1-6. 
Der Augustinismus u. Aristotelismus gegen Ende des 13. Jahrh. 

Arch. {. Litt. u. Kirchengesch. d. Mittelalt., Bd. 5. 
Albertus Magnus. Stimm. aus Maria-Laach, Bd. 19. 
Eisler, M., Vorlesungen iiber d. jiidischen Philosophen d. Mittelalt. Wien, 

1870-84. 
Eisler, R., Philosophisches Wiirterbuch. 3 vols., 3. ed.. Berlin, 1910. 
Endres, J., Alexander von Hales. Philos. Jahrb., Bd. 1. 

Fridugisius u. Candidus. Philos. Jahrb., Bd. 19. 

Die Dialektiker u. ihre Gegner im XI. Jahrh. Philos. Jahrb., 

Bd. 19. 
Othlos V. St. Emmeran Verhiiltniss z. d. freien Kiinsten. Philos. 

Jahrb., Bd. 17. 
Johannes Scotus Eriugena. Philos. Jahrb., Bd. 16. 
Lanfrancs Verhiiltniss zur Dialeklik. Katholik, Bd. 25. 
Honorius .Vugustoduncnsis. Miinchcn, 1906. 



THE SPECIES SENSIBILIS 105 

Die Nachwirkung v. Gundissalinus de Immortalitate Animae. 
Philos. Jahrb., Bd. 12. 
Erdmann, B., Grundriss d. Gesch. d. Philos. 4. ed., Berlin, 1896. 

Der Entwicklungsgang d. Scholastik. Ztschr. f. wiss, Theol., 
Bd. 8. 
EsPENBERGEE, N., Die Philos. d. Petrus Lombardus (Beitrage). Milnster, 

1901. 
Felder, H., Studien im Franziskanerorden. Freiburg, 1904. 
Fischer, J., Die Erkenntnisslehre Anselms v. Canterbury (Beitrage). Miin- 

ster, 1911. 
Forget, J., La philos. d'Avicenne. Rev. Neo-scol., 1894. 

De I'influence de la philosophic arabe. Rev. Neo-scol., 1894. 
Frohschammer, J., Die Philos. d. Thomas v. Aquino. Leipzig, 1889. 
Gangattf, Augustinus Psychologie. Augsburg, 1852. 
Gardair, J., La connaisance. Paris, 1895. 
Gennadius, Opera. Migne, P. L., vol. 58. 
Geyser, J., Wie erklart Thomas v. Aquin unsere Wahrnehmung d. Aussen- 

welt? Philos. Jahrb., 1899. 
Gilbert de la Porree, Opera. Migne, P. L., vol. 64. 
Glossner, M., Die Philos. d. hi. Thomas. Munster, 1887. 
Gonzalez, Z., Histoire de la philosophie. Madrid, 2. ed., 1886. 
French by G. de Pascal, Paris, 1891. 

Estudios sobre la filosofia de Santo Tomas. Manila, 1864. 
German by C. Nolte, Regensburg, 1885. 
Ghabmann, M., Gesch. d. scholastischen Methode. 2 vols., + Herder, 1909. 
Die Erkenntnisslehre d. Kardinals Mathaus ab Aquasparta. 
Wien, 1906. 
Grandgeorge, Saint Augustin. Paris, 1896. 
Ghedt, J., De Cognitione sensuum externorum. Rome, 1913. 
Grtjnder, H., De qualitatibus sensibilibus. Freiburg, 1911. 
Gtjtberlet, C, Psychologie. 4. ed., Munster, 1904. 

Der Kampf um die Seele. Mainz, 1899. 
Der gegenwartige Stand der psychologischen Forschung. 
Philos. Jahrb., 1908. 
GuTTMANN, J., Die Scholastik d. XIII. Jahrh. in ihren Beziehungen z. Juden- 

thum. Breslau, 1902. 
Hammond, W., Psychology of Aristotle. London, 1902. 
Haneberg, B., Erkenntnisslehre d. Ibn Sina u. Albertus Magnus. 
Abhandl. d. philos. u. philol. CI. der k. bayer. 
Akad. d. Wiss., Miinchen, 1866. 
Hatjreau, B., Histoire de la philosophie scolastique. 3 vols., Paris, 1872-1880. 
Hugues de Saint-Victor. Paris, 1859. 
Notices et extraits. 6 vols., Paris, 1890-93. 
von-Hertling, G., Albertus Magnus. Koln, 1880. 
Hoffmann, R., De Joannis Scot. Erig. vita et doctrina. Halle, 1877. 
HoRTEN, M., Buch d. Ringsteine Alfarabis (Beitrage). Munster, 1906. 
Hugh of St. Victor, Opera. Migne, P. L., vols. 175-177. 
HuiT, C, Le Platonisme en moyen-&ge. Annales de philos. chret., 1899-1901. 



106 THE SCHOLASTIC THEORY OF 

Isidore of Seville, Opera. Migne, P. L., vols. 81-84. 

Janet et S6ailles, History of the Problems of Philosophy. (Trans, by 

A. Monahan.) 2 vols., New York, 1902. 
John Damascene, Opera. Migne, P. G., vols. 94-96. 
John de la Rochelle, Summa de anima. Edited by Domenichelli, Prato, 

1882. 
John of Salisbury, Opera. Migne, P. L., vol. 199. 
Joxjrdain, a., Recherches critiques sur I'^ge et I'origine des traductions 

latines d'Aristote. 2. ed., Paris, 1843. 
Jowett, B., Dialogues of Plato. 3. ed.. New York, 1892. 
Kaiser, E., Abelard critique. Fribourg, 1901. 

Katjff, H., Die Erkenntnisslehre d. hi. Augustinus. Gladbach, 1899. 
Kaufmann, D., Die Sinne. Gotha, 1884. 

Kaufmann, N., Die Erkenntnisslehre d. hi. Thomas. Philos. Jahrb., 1889. 
Kaulich, W., Gesch. d. scholastischen Philosophic. Prag, 1863. 

Die Lehre d. Hugo u. Richard von St. Victor. Prag, 1865. 
Kleutgen, J., Die Philos. d. Vorzeit. 2. ed., Innsbruck, 1879. 
Knauer, v., Grundlinien z. aristotelisch-thomistischen Psychologie. Wien, 

1885. 
Krause, J., Bonaventurae de origine et via cognitionis intellectualis doctrina. 

Monasterii, 1868. 
Landauer, G., Avicenna. Ztschr. d. deutsch-morgenl. Gess., Bd. 29. 
Lange, F., Gesch. d. Materialismus. 2 vols., Leipzig, 1905. 
Lanna, D., Le Teoria della conoscenza in S. Tomaso d" Aquino. Firenze, 1913. 
Leder, H., Augustinus' Erkenntnisslehre. Marburg, 1901. 
Lefevre, G., De Anselmo Laudunensi. Lille, 1895. 

Les variations de Guillaume de Champeaux. Lille, 1898. 
Liberatore, M., Institutiones philosophicae. 5. ed., Rome, 1872. 
Liebner, a., Hugo V. St. Victor. Leipzig, 1836. 
Lindsay, J., Scholastic and Medieval Philosophy. 

Arch. f. Gesch. d. Philos., 1902. 
Loewe, J., Realismus u. Nominalismus im Mittelalt. Prag, 1876. 
Lowenthal, a., Pseudo-Aristoteles iiber d. Seele. Berlin, 1891. 
LuTZ, E., Die Psychologie Bonaventuras (Beitrage). Miinster, 1909. 
Maher, M., Psychology. 6. ed., Longmans & Co., 1905. 
Mamertus, Opera. Migne, P. L., vol. 53. 
Mandonnet, p., Siger de Brabant. Fribourg, 1899. 

Manser, G., Johann v. Rupella. Jahrb. f. Philos. u. spekul. Theol., 1912. 
Martin, J., Saint Augustin. Paris, 1901. 

Mathaeus ab Aquasparta, Quaestiones disputatae. Quaracchi, 1903. 
McCabe, J., Peter Abelard. London, 1901. 
Mercier, D., Psychologie. 9. ed., Louvain, 1912. 

La psychologie de Descartes ct I'antliropol. scolastique. Rev. 
Neo-scol., 1898. 
Merten, J., Die Erkenntnisslehre d. hi. .Augustinus u. d. hi. Thomas v. Aquiu. 

Trier, 18G5. 
Michael, E., Gesch. d. deutschcn Volkes vom Ifl. Jahrh. bis z. Ausgange d. 
Mittelalt. Froibur'', 190;5. 



THE SPECIES SENSIBILIS 107 

MicHAUD, E., Guillaume de Champeaux. Paris, 1867. 

MiGNON, A., Les origines de la scolastique et Hugues de Saint- Victor. Paris, 
1895. 
La psychol. de Hugues de S. Victor. Rev. des scienc. eccles., 
1893. . 
MiNGES, P., Erkenntnisslehre d. Johann v. Rupella. Philos. Jahrb., 1914. 
MuNK, S., Melanges de philosophic juive et arabe. Paris, 1859. 
Nagt, a.. Die Philosophic dcs Alkcndi (Beitrage). Miinster, 1897. 
Nemesius, Opera. Mignc, P. G., vol. 40. 

NiEMEYER, J., Dionysii Areopagitae doctrinae philos. et theol. Halle, 1869. 
NouRissoN, F., La philosophic de saint Augustin. 2 vols., Paris, 1866. 
Ostler, H., Die Psychologic d. Hugo v. St. Victor (Beitrage). Munster, 

1906. 
Ott, W., Des hi. Augustinus Lehrc v. d. Sinnes-erkcnntniss. Philos. Jahrb., 

1900. 
Otten, a., Erkenntnisslehre d. hi. Thomas. Paderborn, 1882. 
Pace, E., The Psychology of St. Thomas. Manhattan Quart., 1904. 
Pehrier, J., The Revival of Scholastic Philosophy in the Nineteenth Century. 

New York, 1909. 
Pesch, T., Institutiones psychologicae. Freiburg, 1898. 
Peter Lombard, Opera. Migne, P. L., vol. 192. 

Picavet, F., De I'origine de la scolastique en France et en Allemagne. Paris, 
1888. 
La scolastique. Paris, 1893. 
Le moyen-&ge. Paris, 1902. 

La science experimentale au XIII. sciecle. Paris, 1894. 
Gerbert, un pape philosophe. Paris, 1897. 
Roscelin, philosophe et theologien. Paris, 1896. 
Abelard et Alexandre de Hales. Paris, 1896. 
Esquisse d'une histoire generale et compar^e des philos. medi- 
evales. 2. ed., Paris, 1907. 
Pollak, J., Entwicklung d. arab. u. jiid. Philos. im Mittelalt. Arch. f. 

Gesch. d. Philos., 1904. 
Poole, R., Illustrations of the History of Medieval Thought. London, 1884. 
Phantl C, Gesch. d. Logik im Abendlande. 4 vols., Leipzig, 1855-1870. 
Reid, T., Essays on the Intellectual Powers of Man. Glasgow, 1863. 
Reiner, J., Der aristotelische Realismus in der Friihscholastik. Aachen, 

1907. 
DE Remusat, C, Abelard. Paris, 1845. 

Histoire de saint Anselme. Paris, 1890. 
Renan, E., Averroes et I'Averroisme. Paris, 3, ed., 1866. 

De philosophia peripatetica apud Syros. Paris, 1852. 
Rhabanus Maurus, Opera. Migne, P. L., vols. 107-112. 
Ritter, H., Geschichte d. christlichen Philos. Hamburg, 1858. 
Sanseverino, C, Dynamilogia. Naples, 1862. 
Schaarschmidt, C, Joannes Saresberienses. Leipzig, 1862. 
Schmidt, H., Der Mysticismus des Mittelalt. Jena, 1824. 
ScHMOLDERS, A., Documeuta philos. Arabum. Bonn, 1836. 



108 THE SCHOLASTIC THEORY OF 

ScHiNDELE, St., Beitrage z. Metaphysik d. Wilhelm von Auvergne. Miln- 

chen, 1900. 
ScHNEiD, M., Aristoteles in d. Scholastik. Eichstadt, 1875. 

Die Philos. d. hi. Thomas und ihre Bedeutung f. d. Gegenwart. 
Wiirzburg, 1881. 
Schneider, A., Die Psychol. Alberts d. Grossen (Beitrage). Miinster, 1903. 
ScHREiBER, C, Die Erkenntnisslehre d. hi. Thomas. Philos. Jahrb., 1914. 
ScHUTZ, L., Thomas-Lexikon. 2. ed., Paderborn, 1895. 
ScoTUS Eriugena, Opera. Migne, P. L., vol. 122. 
SiEBECK, H., Gesch. der Psychol. Gotha, 1884. 

Zur Psychol, d. Scholastik. Arch, f . Gesch. d. Philos., 1888-1890. 
SiGHART, J., Albertus Magnus. Regensburg, 1857. 
SoURY, J., Systeme nerveux central. Paris, 1899. 
Stein, L., Die griechische Philos. unter d. xVrabern. Arch, f . Gesch. d. Philos., 

1894, '96, '98. 
Steinschneideh, M., Die arabischen Uebersetungen aus dem Griechischen. 
Leipzig, 1897. 
Alfarabi. Leipzig, 1869. 
Die hebraischen LTebersetzungen d. Mittelalt. Berlin, 

1893. 
Constantinus Africanus. Arch. f. pathol. Anat. u. 
Physiol., Bd. 37. 
Stevenson, F., Robert Grosseteste, Bishop of Lincoln. London, 1899. 
Stockl, a., Gesch. d. Philos. d. Mittelalt. 3 vols., Mainz, 1864-66. 
Storz, J., Die Philos. d. hi. Augustinus. Freiburg, 1828. 
Suarez, F., Opera. Paris, 1856. 
Switalski, B., Des Chalcidius Commentar zu Plato's Timaus (Beitrage). 

Miinster, 1902. 
Talamo, S., L'aristotelismo della scolastica. French trans., Paris, 1876. 
Thomas Aquinas, Opera Omnia. Paris, 1875. 
Turner, W., History of Philosophy. Boston, 1903. 

Erigena and Aquinas. Cath. Univ. Bull., 1897. 
Gerbert, Pope and Philosopher. Cath. Univ. Bull., 1898. 
Ueberweg-Heinze, Gesch. d. Philos. 3 vols., 9. ed. of IL, Berlin, 1905. 
Vacant, Dictionnaire de theol. cathol. Paris, 1868. 
Vallois, N., Guillaume d' Auvergne. Paris, 1880. 
DE Vaux, C, Avicenne. Paris, 1900. 

Gazali. Paris, 1902. 
ViGNA, L., Sant Anselmo. Milan, 1899. 

Walker, L., Theories of Knowledge. 2. ed., New York, 1911. 
VAN Weddingen, a.. Saint Anselme. Paris, 1875. 

Albert le Grand. Paris, 1881. 
Werner, C, Die Psychol, des Wilhelm v. Auvergne. Wien, 1873. 

Der Entwicklungsgang d. mittelalterl. Psychol, v. Alcuin bis 

Albertus Magnus. Wien, 1877. 
Der hi. Thomas v. Aquino. Regensburg, 1859. 
Alcuin u. sein Jahrhundert. Paderborn, 1876. 



THE SPECIES SENSIBILIS 109 

Die Psychol, u. Erkenntnisslehre des Johannes Bonaventura. 

Wien, 1876. 
Die augustinische Psychologie. Sitzungsber. d. k. Akad. d. 
Wiss., Wien, 1882-1884. 
William of Conches, Dragmaticon. Migne, P. L., vol. 90. 
William of Thierry, Opera. Migne, P. L., vol. 180. 
WiLLMANN, O., Gesch. d. Idealismus. 3 vols., 2. ed., Braunschweig, 1908. 
WiLLNER, H., Des Adelard v. Bath Traktat De eodem et Diverso (Beitrage). 

Munster, 1903. 
Winter, M., Avicennas Opus Egregium De Anima. Miinchen, 1903. 
WiTTMANN, M., Thomas u. Avencebrol (Beitrage). Munster, 1900. 
DE WuLF, M., History of Medieval Philosophy. Trans, by P. Coffey, London, 
1909. 
Scholasticism Old and New. Translated by Coffey, 2. ed., 

London, 1910. 
Le probleme des universaux. Arch. f. Gesch. d. Philos., 1896. 
Histoire de la philos. scol. dans les Pays-Bas. Louvain. 1895. 
Les philosophes du moyen-^ge. Paris, 1900-1909. 
Augustinisme et Aristotelisme au 13. siecle. Rev. N6o-sco!., 

1901. 
De speciebus intentionalibus. Div. Thom., 1897. 
Zblleb, E., Philosophic d. Griechen. 3 vols., Tubingen, 1856-69. 
ZiESCHE, K., Die Lehre v. Materie u. Form bei Bonaventura. Philos. Jahrb., 
1900. 



VITA. 

Othmar F. Knapke was born at Cranberry Prairie, 
Ohio, January IStli, 1886. He received his early education 
in the public school of that district, and later pursued the 
academic and collegiate courses of St. Joseph's College, 
CoUegeville, Ind., receiving the degree of Bachelor of 
Arts in June, 1906. In the fall of the same year he 
entered St. Charles' Seminary, Carthagena, Ohio, where 
he was ordained to the priesthood in 1911. Thereupon he 
entered the Graduate School of Philosophy of the Catho- 
lic University of America, choosing as his major study 
History of Philosophy under the direction of Dr. Turner. 
In Psychology, his first minor, and in Ethics, his second 
minor, he followed courses given by Dr. Pace and Dr. Fox 
respectively. He likewise attended courses in Theories of 
Knowledge by Dr. Turner, in Cosmology by Dr. Pace, and 
in Psychology of Education by Dr. Shields. 



X123 



110 






,V^ .\ '.. T.'^ 













^0 O 



^-^ '°-/^ "'" ^'^ <^^ ... "^ 




o". ^'* 













^\ />„ 



. x^^^ 















OO' 



- -^A. V-* 













\ <^' 



0^ *' '^^ / -- 



.V 



v 
o 

^■ 



oo^ 



, % *..o^ y 















v\^ <^ 









V^^ 









'</> v^' ^^^ 









^^^ f 






V^'' ^/> 



"r^^'^^ ,0-^-- 



^>. ^>:::?^ 






# > ^ 






■^^^•^^ » 







.^^^ 







>. e^^- 



^„ 




A- ^"^ - 



V^ ,>;x 



-^..^^ 



^\^ , N r „ f^^ ' 






y/jw- '^^ % ' 



V-^^ C " 



vOc 



^^ ■% 



,0o. 









^. c"^ 



:V • 



■>' ^^ 












:/- 












1% ' 



?^". 



vOo. 






■-^ ,-11'^ ^/'b. ''-'^^ 






*'^;f^\ '" ,^ 








.- ^«-" •'*-. 


■^ S , V -^^ 


•/\..,^ 


\^- 


\^ *■•->- 



"^Z. ^-J^^ 



,P^ V 






LIBRARY OF CONGRESS 



021 060 822 9 



